Margaret

Margaret is a dog, the mother of Jake and Jermaine, and the adoptive mother of Finn. Natasha Allegri has confirmed that she and her husband Joshua adopted Finn as a baby. The couple first appeared in one of Finn's flashbacks in the episode "Memories of Boom Boom Mountain." They find Finn after he has soiled himself, causing him to be stuck to a leaf, and cried for an entire day, all alone in the forest. They are the first and only people to stop and help baby Finn, as all other passersby simply ignored him. Joshua seems to be disrespectful and irresponsible; in contrast, Margaret appears to be caring and loving. The two speak in an 1940s American accent.

According to Finn in "Conquest of Cuteness", Margaret always had "the right thing to say" whenever he or Jake were in a crisis. Strangely, a Two Headed Cutie tried to destroy their respect for her during their invasion, in an attempt to take advantage of their weaknesses.

Quotes
Joshua and Margaret/Quotes

Trivia

 * It is worth noting that in "Memories of Boom Boom Mountain," Finn and Jake both called each other "brother", notably prior to the revelation of the end of Finn's baby flashback. This term of endearment returns several times, including in the episode "Henchman." This further implies that Joshua and Margaret may have partially raised Finn as their own son alongside their own puppies.
 * Pendelton Ward has stated on his Formspring that both of Jake's parents are dead. This is confirmed in "Crystals Have Power", in which Joshua's ghost helps Jake through a personal crisis.
 * Joshua and Margaret were created by taking a picture of Jake and adding different accesories.
 * In Rainy Day Daydream, Jake had a nightmare where he imagined his mother naked. However, Margaret "naked", (without her hat and earrings), would be an ordinary dog like Jake, but to him that could be a traumatic thing.