Beach Koopa

A Beach Koopa is a Koopa Troopa that has lost its shell and wears nothing more than an undershirt (and/or in some cases, boxer shorts), first appearing in Super Mario World. When first knocked out of its shell, the Beach Koopa is extremely vulnerable. If given enough time, it will right itself and pace forwards in search of a new shell. Blue Beach Koopas, however, will kick any shell they come into contact with. The Yellow variety, on the other hand, will go into the shell, where it will flash colors and chase after Mario. Any Super Koopa who wields a flashing cape will revert to a Beach Koopa after being stomped on and relinquishing its feather.

Beach Koopas were also found in Super Mario World 2: Yoshi's Island and Yoshi's Island DS, although here, they walked upright when evicted from their shells, instead of on all-fours as in Super Mario World. This version of Beach Koopas make a small appearance in Paper Mario, as the inhabitants of Koopa Village who have had their shells stolen by Fuzzies.

In the Super Mario World episode "Fire Sale", the silent, Koopa Troopa henchmen of Kootie Pie Koopa is continually knocked out of his shell, becoming a Beach Koopa, in the episode, usually during one of Kootie Pie's violent temper-tantrums.

In Super Mario 64 and Super Mario 64 DS, Mario or others could jump on a Koopa Troopa to knock its shell away, transforming the turtle into a Beach Koopa. If attacked again, the Beach Koopa would be destroyed and a Blue Coin would pop out. If not defeated, the Beach Koopa will frantically attempt to dive back into its shell. Mario can ride on this green shell.

Beach Koopas reappear in Super Princess Peach.

Even Bowser has a "Beach Koopa form" (wearing spotted boxer shorts) when separated from his shell, as shown in the PC version of Mario is Missing!.

In Super Mario Sunshine, Beach Koopas are shown when Mario knocks the shell off of any Koopa Troopa. Mario can stomp on the Koopa in this form to defeat it.

In Super Smash Bros. Brawl in the Mario Bros. stage, the Shellcreepers can be kicked out of their shells, making them resemble Beach Koopas (since they are not exactly Koopas). This is something that obviously cannot happen in the original Mario Bros. game.