Ostro

Ostros are ostriches that Shy Guys ride in Super Mario Bros. 2. They hop along the ground and run back and forth when they don't have a rider. Players can jump on top of an Ostro and ride it across obstacles if it doesn't have a Shy Guy rider. Also, despite their size, Ostros can be picked up real easily, but they don't bounce when thrown.

While Ostros are black in the NES version of the game, subsequent remakes have depicted them as being pink. Like many other enemies from Super Mario Bros. 2, Ostros have yet to make an appearance in a newer game.

The Super Mario Bros. Super Show!
Several Ostros, though usually referred to as Ostriches, appeared in several episodes of The Super Mario Bros. Super Show!, where they were usually riden and used to haul motorless vehicles, much like horses. Due to their role, Ostros never had any speaking lines, and usually made honking noises. They first appeared in the episode "Butch Mario & the Luigi Kid" where several Ostro were used by Mario, Luigi, Snifits and several other characters as steeds to travel through the Wild West. A wild ostrich appeared in "Too Hot to Handle" on the island of Waki-Waki. Mario, Luigi, and Toad rode it to reach Princess Toadstool faster.

Movie
Ostros were also given homage in the Super Mario Bros. movie, which featured a sign with the word "Ostro" on it; this sign is thought to be advertising a company or organization of some sort.

Trivia

 * In the credits and the manual of Super Mario Bros. 2, Ostro's and Birdo's names were switched.  This, like many other mistakes, was fixed in remakes of the game.