Flotsam

Flotsams are spotted stingrays that inhabit the waters of Crocodile Isle. Their name is derived from the word "flotsam", which is leftovers from a shipwreck. Flotsams come in two colors: blue and green. Blue Flotsam swim in only one direction, while the green Flotsam can change their direction from left to right; they generally do this when they reach a wall.

Donkey Kong Land
A Flotsam-like boss appears in Donkey Kong Land, by the name, Wild Sting, a giant stingray boss. It is able to move above water, and must be jumped on several times to be defeated. Alternatively, this stingray could be the creative inspiration or the forerunner of Flotsam.

Donkey Kong Country 2: Diddy's Kong Quest
In Donkey Kong Country 2: Diddy's Kong Quest, Flotsam's are one of the most common underwater enemies in the game, encountered in almost every water-involved level. They simply float through the water and make no real effort in attacking Diddy Kong or Dixie Kong. However if the Kongs are in the path of a Flotsam, it will continue to swim forward, not needing to avoid contact. Flotsam's can only be defeated with help from Enguarde the Swordfish.

Donkey Kong Land 2
Flotsam also appears in Donkey Kong Country 2's pseudo-sequel Donkey Kong Land 2. There is no difference between these Flotsam's and those of Donkey Kong Country 2.

Trivia

 * Floatsam is a similar named enemy in the game Banjo-Kazooie from the Banjo series. However, Floatsam is a rubber ring, while Flotsam is a stingray.