This is a Koopa Troopa from Super Mario Galaxy!
Koopa Troopas are common enemies in the Mario series, usually displayed as foot soldiers of the Koopa Troop, under the direct leadership of Bowser. Since Super Mario 64, however, many Koopas have appeared who do not work for Bowser (or any other villain), some of whom even act as allies to Mario during his adventures. Koopa Troopas are turtle-like creatures with shells that come in many different colors, with red and green Koopa Troopas being the most common. Koopas, along with Goombas, are some of Mario’s most common foes.
By Sabi96