Phinphins are enemies that appear in A Koopa’s Revenge 2. They are designed after the dolphins from Super Mario World. Killing 50 of them in 1 play session will give you the "Tuna!" medal.
Blue Phinphins swim towards the player and jump when they are close enough to the Player.
Purple Phinphins swim from left to right in underwater levels and sections.
Green Phinphins swim straight towards the direction they are facing in underwater levels and sections.