I made designs for PSO J318.5-22, the rogue planet recently featured in a news article here.
Rogue planets (some call it 'orphan planets' are planets that don't orbit any star(either because they are ejected out or formed independently) and are free-floating in space.
I imagine the PSO J318.5-22 as a vagabond kid who is extremely optimistic and quite mature for is age. He has a high survival rate and travels a lot.
He travels with the Beta Pictoris Moving Group, a group of young similar origin stars moving together. Beta Pictoris is the one leading each of their travels. He's a painter who is kinda a fanatic for order and balance (I imagine him as one since Pictor represents 'a painter's easel' haha). Beta Pictoris finds PSO J318.5-22 'out-of-place'.