I found a little critter at a restaurant

It's called a cuckoo wasp because it lays eggs in other wasps nests like the bird. It also does not sting.

is it dangerous tho

No, but since it seeks other wasp nests to lay eggs in, its presence may indicate that there is a wasp nest nearby

Shiny critter

Indeed
I was wondering what it was, because it sure wasn't colored like a wasp
More like a scarab beetle

I thought it was an ant first

Me too, but then it flew around a bit

pet its head.

It was at a restaurant, I am no longer there
Besides it was moving way too much

You found a rare enemy

we getting more xp than normal with this one