Walleye

Walleyes are a new species of Whomp that first appear in the game Super Mario 3D World. They are Wallop-like creatures with spikes on their sides and back.

Super Mario 3D World
Their first appearance was in the level Ty-Foo Flurries. They move from side to side in an attempt to stop the player from walking past them. Contact with their spikes will cause damage, but their fronts and backs are safe to touch. Walleyes can be temporarily dazed by a projectile or a claw attack and can be destroyed by Golden Statue Mario.

Captain Toad: Treasure Tracker
Walleyes are set to return in Captain Toad: Treasure Tracker, having the same abilities as in Super Mario 3D World.