Oso is brave, kind and adventurous. He likes doing training exercises and helping kids out when each one wants to learn something new. Throughout the special assignments, he is always compassionate and encourages them in turn.
Oso is a stuffed yellow bear who likes to pass through training exercises and help kids out. He is important to his friends/helpers, Dotty, Wolfie, Buffo, and Musa, who tell him what to do in every exercise. He fails when he first tries to do them, stops to help a kid (or kids) learn something new, and does the training exercise right with a tip from a child, and earns a training award in the first season and a digi medal for helping a kid out.
Oso sometimes wears other clothes in physical training exercises. He wears a green spacesuit and helmet in space, usually an orange life jacket when he is on a boat, a green diving suit, helmet and flippers when he goes diving, and a blue racing helmet, suit and sneakers when he's riding in his race car. On occasion, he has also worn a tuxedo.
- Sometimes he always likes to help out kids.
- His name, Oso, means "Bear" in Spanish, and he has never even mentioned it.