Nemo

Nemos are aquatic enemies in Donkey Kong Land. They only appear in the level, Nautilus Chase, in which they are the main feature. Nemos are the game's successor to Croctopuses from Donkey Kong Country.

Nemos act very similar to Croctopuses and only have a single behavioral difference from them: Nemos directly chase Donkey Kong or Diddy Kong, whereas Croctopuses swim in a set path.

When the active Kong first encounters a Nemo, it appears to be dormant. As Donkey Kong or Diddy swims past the Nemo, it suddenly emerges from its shell and quickly follows him, including in tight spaces. If the active Kong does not swim fast enough, he gets hit by a Nemo, and therefore injured. Like the game's other aquatic enemies, Nemos can not be defeated. At some point the Nemo quits chasing either Kong, and huddles back up in a corner within the coral.

Their name is taken from Captain Nemo, who pilots the Nautilus submarine in the science fiction novel, Twenty Thousand Leagues Under the Sea.

Reference
Nemo