I was chilling on a little wooden raft-fort, looking for a decent base spot, and all my tames were sitting on a platform on top. My Phiomia (hippo I think his name was) started levitating and ascending. I thought it was just lag, so I moved on. Later I looked and saw he still wasn’t there. So I tried to request him (mobile feature only) but his name wasn’t there. I assume he either drowned, or became God.