Most enemies can be killed either by stomping on them, with a fireball, or a swing of your raccoon tail. While fireballs and tail smacks only provide 100 points, stomping on multiple enemies without touching the ground can lead to additional points. The first enemy in a chain is worth 100 points, and the next are worth 200, 400, 800, 1000, 2000, 4000, and 8000 points respectively. Continuing to stomp on enemies beyond 8000 points will net you one extra life for every enemy killed. Particular enemies may provide a different amount of points.
The traitorous mushroom tribe from Mario's original adventure comes back for more. But there isn't anything that they can actually defend against. Goombas wander in whatever direction they happen to be going, mindlessly falling off platforms as they go.
The Paragoomba is a winged version of the Goomba. He will become a regular Goomba after just one stomp. There are two versions of Paragoombas: the red type that makes small jumps while chasing Mario, and the brown variety that fly and drop Micro-Goombas.
Micro-Goomba
Pile Driver Micro-Goomba
The Micro-Goomba is the smallest enemy of the game. They're dropped by brown Paragoombas. If one of these gets near you, you won't be able to jump high or run fast. Tap the A button rapidly to get them off of you.
The Pile Driver Micro-Goomba is a Micro-Goomba inside a Brick. They like to hide near other Bricks in an effort to surprise you, and then they make huge leaps when you get close. They may be distinguished from conventional brick blocks in that brick blocks usually glisten while Pile Driver's brick blocks do not.
Shoe Goomba
Giant Goomba
The Shoe Goomba is a Goomba wearing a special shoe. If Mario can get it off the Goomba by bumping it from underneath, then he can wear the displaced shoe. Stomping on it or firing it, however, will destroy the shoe as well.
These oversized varieties of Goombas are found in the Giant World. Other than their large size, they are identical to regular Goombas, and can be removed with one stomp.
Koopa Troopas are found throughout the Mushroom Kingdom. Unlike Goombas, a single jump will not defeat it. One stomp will send it hiding in its shell. The shell can be used to defeat enemies, break empty bricks and hit blocks with items. Other attacks, however, will defeat it completely. Green shelled Koopas run mindlessly in one direction and fall over any edge they encounter. Red shelled Koopas are a little smarter and stay on whatever platform they are patrolling.
The Koopa Paratroopa is a winged version of the Koopa Troopa. They can fly around or make big jumps. A stomp removes their wings and turns them into normal Koopa Troopas. However, if Mario hits the block under a Paratroopa, it will tuck into its shell. Other attacks will defeat it completely. There are two versions of Koopa Paratroopa: green and red shelled Koopas. Like their wingless cousins, the green kind tend to move in one direction, while the red ones fly back and forth over a given location.
Giant Koopa Troopa
Giant Koopa Paratroopa
Just like the Giant World variety of Goomba, Koopa Troopas also come in tremendous sizes. They have the same vulnerabilities of normal Koopa Troopas, but their larger size makes them a more dangerous opponent to deal with. When you see a large Koopa shell ricochet against a block and come back towards you, get out of its way!
A few of the giant Koopa Troopas are also capable of growing wings and flying around. Their larger size doesn't necessarily limit their maneuverability through the air, so you must be careful to dodge them when they come flapping towards you. One stomp will make them lose their wings and fall to the ground below, where they proceed like normal (giant) Koopa Troopas.
Mario's high flying antagonist from the original Super Mario Bros. returns. Lakitu is a Koopa that rides in a cloud. He hovers back and forth in the air above Mario, and he tosses a never ending supply Spiny's Eggs to the ground. He can be defeated with any type of attack.
Before Spinys come out of their shell and start crawling around, they start out in this egg state. As eggs, they simply roll along the ground, and bounce off of walls. Just like their mature brethren, do not try to stomp on them.
Spiny
Upside-down Spiny
Spinies are small turtles with spines all over their shell. These spines protects them from stomps. However, if Mario bumps the block under a Spiny or attacks it with a raccoon tail, it will be tuck into its shell. Other attacks defeat the Spiny completely.
These are a special breed of Spiny that can walk along the ceilings of the caves. To attack Mario, they drop to the ground and spin in their shell while sliding along the ground. In order to stop it, Mario can stomp on the shell, hit the block under it or attack it with tail attack. Then he can pick it up and toss it like a Koopa shell.
The Buzzy Beetle is a turtle-like creature with a hard, outer shell. This shell protects them from fireballs. Similar to green Koopa Troopas, they fall from platforms. Jumping on a Buzzy Beetle, hitting it from below, or smacking it with a raccoon tail will make it go into its shell. Like a Koopa shell, a Beetle shell can be kicked to destroy blocks and enemies. All other attacks defeat the Buzzy Beetle completely.
Some Buzzy Beetle possess the ability to walk on the ceilings of the caves. Like the ceiling-walking Spinies, they drop to the ground, and spin in their shell while sliding along the ground. Once on the ground, there is very little difference between these and regular Buzzy Beetles. Try to lure them off the ceiling before passing them.
Buster Beetle
Parabeetle
Buster Beetle is a cousin of Buzzy Beetle that can pick up Ice Blocks and throws them to Mario. However, this ability to lift Ice Blocks has rendered them completely vulnerable to attacks, even fireballs. They may look tough, but other than the ability to toss ice at you, there's no attack that they can survive.
At first glace, Parabeetles may just seem like a winged version of the Buzzy Beetle. However, they're much more useful. Mario can hop on their back for a ride, providing a means to get through certain air levels (making them one of the very few enemies that cannot be defeated by jumping on them). They are immune to fireballs but vulnerable to tail attacks, Star and hammers. Think twice before killing them; they may be your only means of escape.
The Piranha Plant is a carnivorous plant that lives in pipes or in the quicksand. They can even occupy pipes that hang down from the ceiling. However, Piranha Plants won't emerge from their pipe if Mario is touching or standing directly on top of it. They can be killed with many types of attack, but don't try to jump on them.
Giant Piranha Plants only reside in Giant World. They are so big, they don't really notice Mario when he is close to them, so they will rise in and out of pipes regardless of whether you are standing next to them. Take care when making the leap to one of their pipes.
Ptooie
Venus Fire Trap
The Ptooie is a type of mobile Piranha Plant. A Ptooie can be identified by the spiked ball it suspends in the air over its mouth. Occasionally, Ptooies will blow the spiked ball high into the air, turning the space above them into a dangerous place. Like their stationary cousins, they can be killed with many types of attack, except stomping.
The Venus Fire Trap is a Piranha Plant that spits fireballs at Mario. Like normal Piranha Plants, they resides into pipes or quicksand, and they will get shy if Mario is lurking near or on their pipe. Don't try to stomp them, but they won't last against other forms of attack.
Nipper Plant
Muncher
A Nipper Plant is a miniature white Piranha Plant. They patrol an area and leap up at Mario when he tries to pass them. Nipper Plants can hop around, making it difficult for the player to land safely. There's even one Nipper Plant in the whole game which can spit fire. They can be killed with all types of attack, except stomping.
A Muncher is a black, invincible, Nipper Plant. They tend to grow in large clusters. The only way to kill a Muncher is turn it into a coin with a Switch Block. Invincible Mario can walk on Munchers. Some of them are frozen in the ice.
The Hammer Bros. are an elite force in the Koopa army that attack Mario by throwing hammers into the air. While not very common in traditional stages, they wander around the maps of World 1, 3, 5, 6. They tend to appear in pairs, which can make it difficult to find an opening to attack. They can be killed by a variety of methods.
The Boomerang Bros. are like Hammer Bros. except that their weapon of choice is the Boomerang. When they attack, the boomerangs they throw will double back for a second attack from the opposite direction. They appear as map enemies in World 2. They can be killed with any type of attack.
Fire Brother
Sledge Brother
The Fire Bros. are the least common type of the Brother types. Only a few Fire Bros. appear in the entire game; two are found in a secret part of World 2, and another one appears in in the first Hand Trap level of World 8. They have red skin and they spit fireballs at Mario. Like the other Brothers, they are vulnerable to all kinds of attacks.
The Sledge Bros. are a larger version of the Hammer Bro. These tubby turtles have green skin and they throw hammers, albeit slower than Hammer Brothers. Sledge Bros. make big jumps, and if Mario is standing when a Sledge Bro. touches the ground after a jump, he will be stunned. They appear mostly in Giant Land, where they are map enemies. They can be killed with all kinds of attack.
Cheep-Cheeps are the most basic enemy underwater. They come in red and green colors. The red variety swims fast and some red Cheep-Cheeps jump out of the water. The green kind are slower by comparison. Cheep-Cheeps can be killed with any kind of attack, but they can only be stomped on when they are out of the water.
Although the Spiny Cheep-Cheep looks like it might be a bit more of a challenge than it's non-spiny cousins, it's actually pretty much the same enemy. The biggest difference (besides the quills on its back) is that it swims even faster than red Cheep-Cheeps.
Blooper
Blooper Nanny
The Blooper is a common underwater encounter. It will follow Mario relentlessly. You can't stomp on them, or bump them from below, but you can burn them or smack them with a Raccoon tail to remove them and the threat they pose.
A Blooper Nanny is a Blooper with baby Bloopers. When she begins to glow, her kids will form a circle around her and radiate outward. More babies appear to replace the ones she lost a few seconds later. Other than this, they behave just like regular Bloopers.
Big Bertha
Boss Bass
The Big Bertha is a rather large variety of Cheep-Cheep who happens to be a mother. She always carries a child Cheep-Cheep in her mouth. Occasionally, she stops to open her mouth and let her baby swim out and then quickly back inside before resuming her movement. The same attacks that work on Blooper will work on Big Bertha, but you have to be very careful if you try to get up close and smack her with your tail.
Boss Bass is a big hungry Cheep-Cheep. They swim on the surface of the water in search of their next meal. When Mario gets too close, they lunge out of the water. Boss Bass can defeat Mario in one gulp, even if he transforms into Statue Mario. In some of the levels, platforms rise and fall, making Mario an easy target. He's vulnerable to a lot of attacks, but even if you remove him, another one will take his place a few moments later.
Lava Lotus
Jelectro
The Lava Lotus is a large flower that lives underwater. They are capable of generating fireballs under their transparent leaves and releasing them to float up and away. These fireballs can go through platforms and make navigating underwater treacherous. They can release as many as five fireballs at a time.
Jelectros are glowing electric jellyfish that remain stationary in the water. They are invincible, so you can do nothing to remove them from where they are located. Their touch is lethal, and they tend to hang out in groups, so you must be very careful when swimming around them.
Bullet Bills are large black bullets launched by Bill Blasters. Bill Blasters are placed strategically throughout many levels. They can even be found on the ground, where even small Mario can't duck beneath the bullets flying his way. Do your best to avoid them, or stomp them out of the way.
Missile Bill resembles a Bullet Bill that is flashing red. Missile Bill locks on to a target (like Mario), and will turn around once if it misses. Once it turns around, however, it will continue to travel in a straight line until it flies off the screen or is defeated.
Angry Sun
Spike
The Angry Sun is a considerably small sun with an angry face. They are the second least common enemy of the game, making only two appearance; one in the World 2-Quicksand and the other in the World 8-2. To attack Mario, the Angry Sun swoops down in an attempt to hit the plumber before returning to the sky. They can be killed with a Koopa shell, a hammer from Hammer Mario, or by crashing into Invincible Mario.
Spikes are small green turtle-like enemies with an unusual form of attack: they pull spiked balls out of their mouths before throwing them at Mario . Like Lakitus, they have unlimited amounts of ammo. The spiked balls fly straight across and they can even pass through blocks and terrain. Spikes are vulnerable to all types of attack.
Bob-omb
Chain Chomp
Bob-omb is a living bomb. They are often launched by cannons, but occasionally they appear walking on the ground. If Mario stomps on one, it will become stationary and capable of being picked up and used as a weapon. However, it will explode in a few seconds, even if Mario is still holding it. Later on in the Bowser's Tanks, Bob-ombs self-destruct after a few seconds from when they appear. They can't be destroyed with fireballs, but they can be taken out by explosions from other Bob-ombs.
Chain Chomps bear a resemblance to a ball and chain and have very dog-like behaviors, including barking. They're attached to a block, but if 160 seconds go by, they are set free. There are four ways to defeat Chain Chomps: using a Star, throwing a Koopa shell or a hammer at it as Hammer Mario, and stomping on it as a statue from Tanooki Mario.
Fire Snake
Fire Chomp
The Fire Snake is a flame with four fireballs behind it. Fire Snakes chase Mario in an effort to set him on fire. They hop from one location to another, in whatever direction Mario happens to be. They can only be defeated by either hitting it with a Shell or Hammer, by using an invincibility star, by hitting it with a raccoon tail, or a stomp from Statue Mario.
A Fire Chomp is a cousin of the Chain-Chomp, but it's held together with four fireballs instead of a chain. They are capable of flying, and they spit fireballs at Mario. When they run out of fireballs, they chase Mario before they explode. They can be defeated with stomps, hammers, Star, and tail whacks.
Boo is a small white ghost. Boo is incredibly shy, and he will stop in his tracks and shield his face whenever Mario looks at him. Once Mario looks away, they will resume their chase. Boos can be defeated only with hammers or Invincible Mario.
Dry Bones is the animated skeleton of a Koopa Troopa. When you stomp on Dry Bones, they collapse into a pile of bones. Moments later, however, the bones will rise back up off the ground and come back to life. The only ways to destroy them permanently are with a Star or the Hammer Suit. Unlike normal Koopas, Dry Bones is immune to fireballs and raccoon tail attacks.
Bowser's Statue
Hot Foot
Bowser's Statues are sculptures of King Bowser himself that you will find in Bowser's castle. They're more than just egotistical decoration; many of them are capable of firing lasers. The lasers they shoot are fired down to the ground in a 45 degree angle. These statues are indestructible.
Hot Foot is an animated flame that inhabits candles. Their behavior is similar to Boos. If Mario faces one, it will stand still. Once Mario looks away, it will resume walking towards them. Hot Foot can only be defeated by throwing an hammer as Hammer Mario at it or with invincibility.
Podoboo
Roto-Disc
The Podoboo is a large fireball that leaps straight up out of lava. They appear in a number of fortresses and in the second Hand Trap level of World 8. Although you must mostly dodge them, it is possible to defeat them with a hammer or with Invincible Mario.
The Roto-Disc is a glowing energy disc that spins around a block. Mario must time his passage around them very carefully in order to avoid collision. It can only be destroyed by one means: with Tanooki Mario's statue stomp.
Thwomp
Stretch
Thwomp is a living square rock. They try to squash Mario under their weight whenever he runs beneath them. Thwomps try to detect when Mario is getting close, and then crash down to the ground. You can trick them into falling, and this is often required in order to survive passage past them. As strong as Thwomps are, they can't harm Tanooki Mario in statue form.
Stretches are a type of Boo that's attached to a platform. They are found exclusively in fortresses and are more of an obstacle than a true enemy. As Mario attempt to pass, a Boo will rise from the top and bottom of the platform and slide along the surface. Stretches are usually found in groups, making them a formidable foe. Stretches can only be defeated with hammers or with a Star.
Cannonballs are heavy metal spheres that are launched from cannons at high speeds. They can be defeated primarily through physical attacks: a stomp, a hammer, a Statue stomp or with Invincible Mario.
Rocky Wrench is a mole with a black shell. Upon sighting Mario, a Rocky Wrench will pop out of its hole in an airship or vehicle, and chuck wrenches at him before descending back into its hole. They can be killed with all types of attacks.
Rocket Engine
The Rocket Engine is a flame of gas that comes out of cylindrical blocks. They are positioned in annoying places. Tanooki Mario can actually defeat these flame jets by transforming into a statue and stomping them. However, a new flame will appear after a few seconds.