[cheebacheeba]

I know there's a thread but I couldn't find it, didn't really look....mods feel free to move this...

Anyways, I think I may have asked about it before. Perhaps in here or elsewhere, but my search didn't yield any results.
It's kind've annoying me so I'll give it another shot.

Ok.

It's definitely a late 80's to early 90's film.
It would be under...hm...fantasy/adventure/comedy.
The setting was modern, it was a US made film.

I thought it was called "sub-something", maybe "under-something"

The main character in the movie was a guy that was maybe in his late teens.
The secondary character was a creature, walked somewhat upright but wasn't really humanoid - it was quite scruffy/hairy from what I can recall.
In my mind, it may have looked something like those things from the second Bill&Ted movie. Maybe.

The creature came from some kind of city/place that was underground.
I have a feeling that the movie actually had the same name as this place or whatever they referred to it as.

I think it was either trapped in the human world or something was wrong with its own.

I remember it being fascinated with shoes or shoelaces? Took the main characters shoe/s multiple times.
It may have "stolen" a few other things too.

I remember a scene at a police station.

I remember the poster/cover for this film had the main character leaning back to back with the creature - reminiscent of the cover of "little monsters" but with the human being taller than the creature.

...and that's it.