“ | that's a comically weird sign for a slaughterhouse | „ |

Appearance
It looks like a human with long limbs that's split down the middle and either has extremely long legs and is standing above a sign or is floating above the sign.
On his CuriousCat profile, Trevor says that it is someone that was split in half from a big accident, so it is implied that this is the ghost of him.
Trivia
- The creature looks to have some sort of intelligence as it was able to move the sign letters around.
Source
https://twitter.com/slimyswampghost/status/1025621166302679041