I've an idea for a circus strongman.
He would be a bugbear (having powerful Build) as well as the brawny feat (UA - so would require approval).
I was thinking he could have the marine background. He joined the circus after he ended his military service.
He was initially hired as one of the crew [Tool Proficiencies: Vehicles (land & water) + Steady (Additionally, you can automatically find a safe route to land a boat on shore, provided such a route exists.)]
But it was soon discovered that he was unbelievably strong, so an act was made for him, for when they weren't on the waters between ports.
He would be a ranger (Primeval Guardian, which I mentioned to the GM in a private message, and would need approval), so could increase his size to large, which would increase his lifting capacity as well.