???

Also known as Shadowy, "???" is a side character that lurks in the remains of Slime Block's laboratory. Its intentions and identity is currently unknown.

Shadowy was first seen by Spider Head, when they approached her with supposedly vicious intent, although this cannot be directly confirmed, as they did not speak or do anything.

Shadowy's true identity was officially revealed after OSS's cancellation to be Magma Cream, who entered the Lab with the intent of stealing something and then burning it down.