|Some nerd in Max's class. Hopes to someday pilot two gundams|
Jeff's most notable attribute is his complete and total nerdiness. He has an interest in stereotypically geeky things, such as video games. He also seeks attention, due largely to his lack of friends, and is seen being quite upset when Max decides against sitting next to him at lunch, but overjoyed when Max later calls him his buddy.
Jeff came into the foreground when he was attacked by Hijack, who took control over his body, causing him to act far more serious and violent than his usual self. In an attempt to access the Principal's Office, the Hijack-controlled Jeff began using extremely powerful throws in that day's game of hitball, hoping to seriously injure someone.
- Jeff's full name was initially given as "Jeffrey". It was later retconned to "Jeffavorite".
|The Activity Club||The Consortium|
|Edward Burger | Isabel Guerra | Isaac O'Connor | Maxwell Puckett||Agent 13 | Boss Leader | Cinnamon Stix | Agent Day | Francisco Guerra | Greco Stucks | Texas Walker | Mina Zarei|
|Ms. Baxter | Vice Principal DuNacht | Mr. Garcia | Coach Oop | Mrs. McJohnson | Principal Pleezdoo | Mr. Puckett | Mrs. Puckett | Richard Spender | Mr. Starchman||Angry Band Kid | Ball Golem | Damien | Damien's sister | Dimitri Danger | Doghouse | Fitzgerald | Jeffavorite Flavors | Johnny Jhonny | Cody Jones | Lisa | Ollie Oop | Zoey Puckett | R.J. | Sam | Collin Sloinne | Stephen | Student Council | Susan | Violet|
|Spirits and Ghosts|
|Butterfly Ghost | Doctopi | Doorman | Eightfold | Flipflop | General Emerald | Forge | Ghost Train | Gorf | Hijack | Hissin' Pete | King C. | Lefty | Lucifer | Muse | Night Lamps | Nin | Patchworm | PJ | Queen of Kindness | Ravenous Gobbledygook | Scrapdragon | Sphinx of Games | The Shadow | Venus Guytrap | Vile Spirits|