I'll say tightrope walker. And I keep forgetting it's Sunday... so was I suppose to answer on Monday? Anyway I hope my answer still counts..

I'll go with the tightrope walker.

I'll go with sword swallower.

Tightrope Walker. If you ‘ambulate’ you are walking.

Well, I surprised myself with that one! !

Yes, as Outside Playing said, 'ambulate' is walking, so it just about has to be tightrope walker. Although the 'fun' as the first syllable makes me think maybe a clown? They walk, too.

Rusty

I'll choose circus clown.

You mean it's not *that* guy at a party that puts a downer on the whole place? :-D

I'll go with the tightrope walker too.