Arlette
I have no idea. I fiddled with Fionna a bit for DragonCon and did the group with my girls (and boy) again.
Fionna - Me
Manly Finn - Jon
Marceline - Chiara Scuro
Princess Bubblegum - BeckyTaka
Flame Princess - Brandy (I don't know her cosplay name, whoops)
Photo by Lionel.