Short description: A story about a reaper, who pretends to be a mortal, just so that he can hang out with his oblivious human friend.
Morty is a reaper, and he's annoyed by the fact, that mortals see him as a skeleton with a scythe. Those who see him as his "real" self are either scared of him, or about to die, so he feels pretty lonely. He doesn't like to hang out with his reaper colleagues either.
Finally, some day later, he meets a person to hang out with, but he pretends to be a mortal himself. He's scared that they might leave him too if he tells the truth.