​death’s dynamic shroud
そんなK.U.G. (SUCH K.U.G.)
Kug was used as an early test enemy, but he can be can be seen in the final game
Just not easily

Kug is under the ground below the clam ride in episode 8 of Pinna Park
Using an Action Replay Moon Jump code, you can fly high enough to go through the top of the mountains and walk over to Kug
Though because of its location, it's hard to get a good look at it

Here’s a screenshot of the best view of Kug underground

Trying to jump on it electrocutes Mario