Jeffy (also known as Jeffy Jeffy or Jeffy François) is one of the main characters of the SuperMarioLogan series. He is the former son of Nancy and the late painter, Jacques Pierre Francois and the adopted son of Mario and Rosalina.
Despite being a protagonist, Jeffy is occasionally antagonistic.
He is voiced by Lance Thirtyacre. His animal noises were provided by Anthony Miller.
Jeffy also appears in Puppet Pals as one of Pink Evil/Pink Awesome's best friends.
Jeffy is dimwitted and likes to put pencils in his nose, putting his pee pee in stuff and spank his diaper. He can easily cry and bang his head on things when he is called a bad boy.
He can also act rude, angry, demanding, and disobedient.
Despite his bad behaviour, Jeffy has done several good deeds such as being considerate to Hansel by feeling genuine pity for him and giving him his bike in Jeffy's Bike!, saving Santa Claus from choking, stopping Drawing Jeffy from playing with a gun, helping Mario stop The Robber, genuinely thinking of Mario and wanting to give him the egg, giving his shirt to a chicken when he was outdoors so it wouldn't get cold (causing Mario to think Jeffy turned into a chicken), wanting to use a birthday wish which stops everyone dying from the solar eclipse (even though Brooklyn T. Guy used the wish instead), deciding to be a detective to prove that Mario is innocent and stopping an armed robber which caused him to be hired as a police officer. He even occasionally saves Mario from floods and fire in Puppet Pals videos.
He is most likely misunderstood after being abused by his biological mother and witnessing the death of his twin sister.
- Jeffy's birth mother, Nancy would be the reason why Jeffy has bad behaviour since Nancy abused Jeffy for no reason.
- Although Jeffy has become a teenager in August 21st 2017, he does not act like one.
- Despite being born in 2004, Jeffy has gotten a cheerio box pregnant and Brooklyn T. Guy helped Jeffy and The Cheerio Box give birth to Puss Hole 1, Puss Hole 2 and Jeffy Junior in a 2017 video, Jeffy Has Kids!.