The Subspace Emissary
Petey Piranha
A giant Piranha Plant that acts like a baby. During the Subspace Emissary it carries two cages with Peach and Zelda in that it swings around and smashes together. The cage you break open changes the direction of the storyline slightly.
Ridley
The winged leader of the Space Pirates. He flies around, using his claws and tail to attack. He may crash down on the ground or fly around in a loop to knock you away.
Meta Ridley
An enhanced, bionic form of Ridley that attacks while you ride on the back of the Great Falcon. He attacks by swooping across the screen or launching fireball attacks.
Rayquaza
A legendary Dragon Pokémon that thrashes about and launches Energy Balls and Thunder bolts. It may also fly into the air and dig into the ground or dive down onto your location.
Porky
A greedy little brat from Onett who appears in his spider mech from Mother 3. He stabs around with its claws and launches laser and electric attacks.