Jeffy

Jeffy François is the chaotic, adoptive man-child whose bizarre origins and destructive antics form the backbone of the series' modern lore. Born on August 21, 2004, to a wealthy yet highly neglectful French painter named Jacques Pierre François and a hyper-aggressive woman named Nancy, Jeffy spent his earliest years experiencing severe head injuries—most notably being dropped on his head multiple times—which caused his signature cognitive delays and his constant compulsion to shove a No. 2 pencil up his nose. In 2016, Nancy abandoned Jeffy on the doorstep of Marvin with a note and a box of Cheerios, kickstarting a turbulent domestic dynamic where Jeffy relentlessly tortures Marvin with catchphrases like "What doing?", aggressive diaper-slapping, and extreme property damage, all while being enabled by his biological sister, Feebee, and his favorite green toy piano. he absolutely hates green beans. The lore took a massive cinematic turn during his 18th birthday saga, which revealed that Jeffy was the sole heir to his deceased biological father's staggering $200 million fortune; this sparked a violent, high-stakes conflict with Nancy, who returned to extort and murder him, ultimately leading to her death and cementing Jeffy's status as a fabulously wealthy, yet utterly oblivious and unhinged, permanent legal dependent of Marvin.