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 after reaching a wall.

Donkey Kong Land
A Flotsam-like boss appears in Donkey Kong Land, by the name Wild Sting. 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; the two games had overlapping development periods due to both being released in 1995, so either is a possibility.

Donkey Kong Country 2: Diddy's Kong Quest
In Donkey Kong Country 2: Diddy's Kong Quest, Flotsams 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. Flotsams can only be defeated with help from Enguarde the Swordfish.

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

Trivia

 * The manual for Donkey Kong Country 2 misspells Flotsam's name as Floatsam in the same section where it's titled "Flotsam".

Floatsam