Sandshrew, Squirtle, Mudkip and the female Rhydon are from Nintendo's Pokemon and this screenshot's taken from Valve's Garry's Mod.

Big Mama Rhydon wants to fave fun with her adoptive kids by allowing them to hold on to her horn and spin it in correct speed and carefully enough not to make them fly up into the sky. It looks like they're having fun and she's glad to spend time with them like a good mother.