Colos Yearling

Creature — Goat Beast1/1$0.14

Mountainwalk (This creature can't be blocked as long as defending player controls a Mountain.) : This creature gets +1/+0 until end of turn.

Legal in Commander

Is

Commanders whose abilities work with this card and share its colors, from what the cards do.

Slinza, the Spiked StampedeColos Yearling is a Beast, which Slinza, the Spiked Stampede can use.
Jandor, Fortuned TravelerColos Yearling is a Beast, which Jandor, Fortuned Traveler can use.