If you were playing Bilbo in DnD 5e, the class that makes the most sense to give bilbo is Rogue. Commoner isn't a class; bilbo could only be one if he was an NPC.
Does he exactly map onto the DnD rogue chassis? No, he doesn't, but he maps worse onto every other class.
Okay, but technically, incubus/succubus means demon who lies on top/beneath
Its summon top or bottom, not summon male or female