Mecha Cheep

Mecha Cheeps are mechanical versions of Cheep Cheep that first appear in New Super Mario Bros. U. They have metal fins and a wind-up key at the back similar to that of Mechakoopas.

New Super Mario Bros. U
In the game, Mecha Cheeps appear only in the level The Mighty Cannonship. They are impervious to fireballs, but can be defeated with an Ice Ball or Super Star, or by leading a Targeting Ted into them.

Mario Kart 8 / Mario Kart 8 Deluxe
Mecha Cheeps appear in Mario Kart 8 and Mario Kart 8 Deluxe in the underwater section of Water Park and on posters seen in the entrance to the Sub Coaster at the beginning of the course, showing its structure. These posters say that the Mecha Cheeps have a built-in artificial intelligence system in their heads, and that their mouths function as inflow ports. The wind up key at the back provides the Mecha Cheep's propulsive power, and the dorsal fin acts as a leveling fin. Their steerage is apparently located in the underside of the fish, towards the tail. The poster also details the fuel efficiency as 888 mpg, and their serial number as 0026-2814.

In Mario Kart 8 Deluxe, a Mecha Cheep also appears inside the bathtub in Squeaky Clean Sprint.