Cool Sword: Joshua was the original owner/creator of the Demon Blood Sword.Battle Couple: They're Happily Married and both of them work together in their monster hunting business.Neither of them has stretchy powers like Jake but are shown to be able to handle enemies powerful enough to beat their super-powered sons easily. Badass Normal: By Ooo's definition of normal, anyway.She seems to favor a crossbow and shuriken. Action Girl: Margaret, who forms half of Joshua and Margaret Investigations, definitely qualifies.In his final message, he tells Finn that he loves him and that he knows he'll do great things. However, it's clear that Joshua just misjudged how hurtful his words would be to Finn, as he only said those things as a method of Tough Love rather than out of malice. The harsh words coming from both his brother and father (the latter of whom Finn hasn't seen in years due to Joshua's death) nearly causes Finn to kill himself. In the prerecorded messages he left for Finn and Jake in his dungeon, he hurls insults at Finn and convinces Jake to do so as well. Abusive Parents: Joshua is a downplayed example.

Their job is to hunt monsters around Ooo. Jake's parents, who also adopted Finn after finding him in a forest. Voiced by: Kent Osbourne (Joshua) and Maria Bamford (Margaret)