Now that we have pets that we can ride into hostile environments we need a way to not lose our pets if we die. How about a cage that brings your pet back to you? If you die while riding your pet unicorn just set your teleport cage down and your unicorn will teleport into the cage.
The cage can be made on a diamond portal. It would require a cage, a platinum block, a portal, and 200tc. The cage would have to be linked to the unicorn before riding him or it would not be able to teleport him.