Train enthusiast

Laughs in 3-cylinders

Or 2 if you're strapped for time

I just tried this and I think it's correct (as long as its multiplied with the natural numbers excluding 0)

Besides that, I'd claim that choo choo must always come in a quantity of exactly two at once.

Edit: No, actually I take everything back because trains should be electrified and not need to make these sounds.