So I just found a cave the one that holds the artifact of the hunter if my memory is correct I had a Yuty and a Rex on follow I just walked in not very far to avoid creatures and suddenly somehow my Yuty just walked into the cave and I could just ride it. I was on ark ume.

So:

Human: I’m gonna explore the cave

Rex: no its dangerous I can’t follow you inside

Yuty: I’m going in

Human: what’s that? (See the Yuty) how the giga did you get in here!

Yuty: I’m not letting you go in here alone