A ghost, just that you were alive. Wow, I really wouldn't have ever guessed that specific detail. At some point I did think 'ghost' but I threw that theory out after talking to you that other time.

[Mouri is actually amused by that. Mettaton is a robot and a ghost at the same time, technically, so...]

If somehow there's also a werewolf in this place then every popular creature humans kind of believe in will be shown to exist somewhere. Not that anyone back home will ever believe I met them.

[Megumi coming from a place filled to the brim with zombies counts for the list]