Currently, sentient_tail is aliased to living_tail.

I think it should be the other way around, the tag should be sentient_tail, to match sentient penis.

Why: Unless the blood flow to the tail has been cut, or it's not made out of living material, pretty much all tails are living. They have cells in them that are alive. The unique thing going on with the tag living_tail is sentience. So, we should use sentient_tail.