New Super Mario Bros. Wii/Enemies

Goombas
Denizens of the Mushroom Kingdom who have turned traitor and now serve the Koopa Troop. They can be flattened with a single stomp or defeated in all sorts of ways. A goomba with wings, essentially. Stomping it grounds the goomba, which can then be dealt with as above. Tiny gommbas that can appear in a few worlds. These can't hurt you, but if they get onto you, they can crawl all over you and slow you down. If that happens, Spin Jump to shake them off. A large goomba twice the normal size. Normally seen in the World 1 enemy ambush. Stomping one causes it to split into two regular-sized goombas. As if Grand Goombas were big enough, these huge critters are four times the normal size and split into two grand goombas when stomped.
 * Goomba
 * Paragoomba
 * Micro Goomba
 * Grand Goomba
 * Mega Goomba

Koopa Troopas
The rank and file of the Koopa Troop, these turtles will walk the levels, turning when they hit a wall or other enemy but walking off ledges. Stomping them once causes them to retreat into their shells, which you can pick up and/or kick along the ground. A koopa shell can defeat other enemies as they slide along the ground but can also hit you, too! Unlike their green counterparts, Red Koopa Troopas patrol smaller areas because they turn around at a ledge. Otherwise, they act the same. Koopa Troopas with wings that let them fly. They can be seen flying either in back-and-forth patrol paths or simply moving along in a certain direction. Stomp them once and they'll be grounded, reverting to the walking patterns dictated by their shells.
 * Green Koopa Troopa
 * Red Koopa Troopa
 * Green Koopa Paratroopa
 * Red Koopa Paratroopa

Piranha Plants

 * Piranha Plant
 * Venus Fire Trap
 * Super Piranha Plant
 * Super Venus Fire Trap
 * Stalking Piranha Plant
 * River Piranha Plant
 * Muncher

Hammer Bros.

 * Hammer Bro.
 * Boomerang Bro.
 * Fire Bro.
 * Sledge Bro.
 * Ice Bro.

Beetles
The annoying spiked-shell critters that are constantly thrown by Lakitu. Their spikes mean you can't stomp them, but they will react to just about anything else. These critters may wander a level in the same way as a Green Koopa Troopa. You can stomp, carry, and kick them like Koopa Troopas, but their special shells mean they don't react to fireballs, but they will react to other things. Also remember that Buzzies can sometimes be seen crawling on ceilings. If you see one like this, they will drop from the ceiling and spin towards you when you get close. The worst of both worlds, a Spike Top can neither be stomped (because of its namesake spike) nor fried (because it has the same type of fireproof shell). Also, they are very skilled at crawling along walls and ceilings, tuning the corners quite easily so as to keep going. But there are ways to beat them (shells, Starman, knocking around the block they're walking along, etc.). Unlike other winged creatures, Para-Beetles are virtually invincible. Indeed, you usually don't want to defeat these creatures because they tend to appear in wide-open areas; you'll need to hop on their backs and hitch a ride in order to get across the vast empty expanses they cross. These larger versions will appear in only one course. They have difficulty enough as it is flying so the moment you land on it, Heavy Para-Beetles will start to sink from the sky. Be sure to find another place to land before it takes you with it.
 * Spiny
 * Buzzy Beetle
 * Spike Top
 * Para-Beetle
 * Heavy Para-Beetle

Cheep-Cheeps

 * Cheep-Cheep
 * Mega Cheep-Cheep
 * Deep-Cheep
 * Mega Deep-Cheep
 * Spiny Cheep-Cheep
 * Cheep Cheep School
 * Porcu-Puffer
 * Cheep-Chomp
 * Fishbone

Other Water Enemies

 * Blooper
 * Blooper Nanny
 * Baby Blooper
 * Urchin
 * Mega Urchin
 * Huckit Crab
 * Clampy
 * Bulber
 * Jellybeam

Artillery Enemies

 * Bullet Bill
 * Banzai Bill
 * Missile Bill
 * Missile Banzai Bill
 * King Bill
 * Bob-omb
 * Para-bomb
 * Chain Chomp
 * Fire Chomp
 * Amp
 * Rocky Wrench
 * Mecha-Koopa

Ghosts

 * Boo
 * Big Boo
 * Circling Boo Buddies
 * Broozer
 * Scaredy Rat
 * Ghost Vase
 * Crowber

Fire Enemies

 * Podoboo
 * Fire Snake

Others

 * Monty Mole
 * Swooper
 * Pokey
 * Bramball
 * Spike
 * Stone Spike
 * Wiggler
 * Mega Wiggler
 * Cooligan
 * Fuzzy
 * Mega Fuzzy
 * Foo

Object/Obstacles

 * Cannon
 * Cannonball
 * Giant Cannonball
 * Rocket Engine
 * Spiked Ball
 * Giant Spiked Ball
 * Spiked Pillar
 * Giant Spiked Pillar
 * Ball 'n' Chain
 * Firebar

Fortress/Castle Enemies
The re-animated remains of long-dead Koopas. They are fireproof, and if you stomp one, it only stays down for a few seconds before reassembling itself and starting up again. You can smash them for good, however, if you freeze them first. A larger Dry Bones that requires Ground Pounding to break apart. They will react to freezing, but they can break out much more quickly. Huge stones that sense intruders and will drop themselves to the ground if you get too close. Try to lure them into dropping then getting out of the way. Then you can cross as they try to get themselves back up to dropping height again. Pretty much as one can picture it: a much-larger piece of rock that otherwise acts the same way. Still, being so big, getting out of its way can be rather tricky, especially since it's so heavy that it can smash through bricks, meaning they can't be relied upon for protection. But since it's so big you may find crevices in the floor you can hide in to avoid its crushing bulk.
 * Dry Bones
 * Super Dry Bones
 * Thwomp
 * Super Thwomp

Bosses

 * Larry Koopa
 * Roy Koopa
 * Lemmy Koopa
 * Wendy O. Koopa
 * Iggy Koopa
 * Morton Koopa Jr.
 * Ludwig von Koopa
 * Kamek
 * Bowser Jr.
 * Bowser
 * Giant Bowser