One can't hang by a tail.

Slow tail!
(That is, “Don't get angry.” When the Na'vi get angry, their tails whip around, so “slow down your tail” is another way to say calm down.)

The tail and ears also speak.
(The idea is that someone's words might not match their attitude, expression, behavior, etc.)

He steps on tails.
(I.e. He is socially awkward.)

Forgive me. I didn't notice that your tail was in front of me.

She used her tail to point out the tree Loak was hiding behind.