|Role||Jacknife the Escapee|
Jacknife is always escaping Superjail and committing crimes that land him back in every time. While he has no prominent role in the episodes themselves, Jacknife committing a crime and being caught by Jailbot is a running gag at the beginning of each episode (minus six) that leads up to the end of the intro. Voiced by Christy Karacas.
He seems to have gotten his criminal ways from his father, which was shown to also have a total disrespect for life, including his own son's. As he sold his toys for booze which caused Jacknife to have so much pent up sadness that years he teared up and pushed a boy away from his own toys to play with himself. 
Jacknife is a low-level pervert and social delinquent with no apparent morals, judgment or sophistication. Apparently incapable of normal speech, he expresses himself through noises ranging from lecherous grunts and chuckles to groans of horror and squeals of pain. His various poorly-planned criminal activities are cataloged at the beginning of each episode and inevitably end up drawing Jailbot's attention and getting Jacknife severely beaten and hauled back to Superjail.
His rap sheet includes:
- assaulting an old woman and stealing her clothes in order to get free drinks at a bar,
- grave-robbing (followed by necrophilia when he found a lady corpse he liked)
- dressing up as Santa Claus to steal medicine from terminally ill children
- stealing a car and running over the owner
- assault, theft, stealing a speedboat, and stalking/peeping at a teenaged girl.
Although his criminal nature is generally a constant, in Oedipus Mess, The Doctor states that he has "...a microscopic quotient of selfless love..." which may be proven when, in the same episode, Jack Knife presumably crafted a hanging mobile for his genetic son and taught him to tunnel through walls.
Relation to Other CharactersEdit
Jailbot - They have a cop and robber relationship as he is always being caught (and violently beaten) by Jailbot. In "Best Friends Forever" it was shown that both have a strong love/hate thing going on.
The Warden - In "Bunny Love" the Warden gets angry at him because he killed a bunny, going so far as to call him a "sick bastard". In all the other episodes, he gives him no special interest or interaction.
Hunter - They "kiss" and she transforms to human-like woman, then she knees him in the crotch before throwing him into a wall.
Jacknife's father - At a young age, Jacknife seemed to dislike his father, mostly because that he sold his favorite toys at a pawnshop to get liquor. While trying to escape Superjail he meets up with the ghost of his father and the two hug while crying profusely suggesting they missed each other after many years of being apart. However, they then start to attack each other for some unknown reason and on the other side they are shown to continue fighting stabbing each other.
Jacknife's son- In one episode he is revealed to have sired a son upon seeing the boy he quickly escaped superjail but was cloned repeately and said clones were killed until the original remained and was given care of his crying child. At the end of the episode he and the child escaped the prison and the child calls jacknife "da-da" making jacknife groan (not liking the idea of being a father.)
- Jacknife escaping Superjail is the only continuity in the series. (Example: In the Bunny Love Pilot the Monday Mystery Meat broke through the walls and Jacknife escaped for the first time.)
- There are six episodes in which he is not brought to Superjail in the beginning:
- In Cold-Blooded, Jailbot accidentally brought the Monster Convict to Superjail instead, the latter having skinned Jacknife and used his face as a mask.
- In Time-Police Part 2, Jacknife was brought to a Real Jail after a botched attempt at a bank robbery.
- In Best Friends Forever, he was in custody of Jailbot, but was let free by Jailbot at the end of the episode.
- In Jailbot 2.0, he is taken out of SuperJail by a malfunctioning Jailbot back to his town where he runs off after the robot shuts down.
- In The Budding of the Warbuxx, he doesn't appear in the episode marking his very first absence.
- In Stingstress, a female who looks like him is brought to UltraJail in the beginning.
- He only speaks in grunts, groans and squeals.
- He is not shown escaping in Combaticus, Don't Be A Negaton, Dream Machine, or Mayhem Donor.
- He's been killed once in the series by Hunter in Hotchick.
- In the above trivia statement as well as to popular belief, it wasn't Jacknife because (although his hair was like Jacknife's) when he got caught by the Hunter, his hair was down instead of straight up. The camera zoomed in on him just to confuse the viewers.
- He seems to have a soft spot for children.
- In the episode Ghosts, Jackknife can be seen making up with his father (suggesting he has since passed) before both started to attack each other. And back in the space between crossing over you can still see them fighting (stabbing each other). This was the first time he actually died, but he was still "alive" because we don't actually see him dead as a corpse.
- He is seen playing with a Lord Stingray action figure (this is due to him trying to relive his past since he had all his toys sold for booze) before the actual character is revealed in the series for the first time to viewers.
- In Oedipus Mess, Jacknife is described by Jared to be Superjail's most vile inmate. This means he is more dangerous than the other prisoners no doubt due to his upbringing and violent crimes.
In Stringstress, a female look a like of him appears which could possibly mean he has a sister or wife.