The nonexsistient Episode titled Finn's Relatives, is about Finn meeting his relatives, Charlotte, Chad, and Lilla
'Synopsys
Finn is walking through Ooo with Jake and Jasmine, Finn's girlfriend, and they bump into a blond girl, who looks almost identical to Finn, except she's a girl, and she doesn't wear a hat and is wearing green, and that girl introduces herself, as Lilla, then she introduces her brother and sister, as Charlotte and Chad who also look identical to Finn,no hat's just blue, so they all go to the universal history library, and find out that Finn and Lilla are twins, and Charlotte and Chad are his younger siblings.