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Background information
Feature films The Secret of NIMH
Television programs
Video games
Park attractions
Portrayed by
Portrayed by
Voice Paul Shenar
Performance model
Honors and awards
Inspiration The character of the same name from the book "Mrs Frisby and the Rats of NIMH"
Character information
Full name
Other names
Personality Bloodthirsty, abrasive, pompous, vain, cruel, traitorous, sneaky, unkind, self-absorbed, strict, ill-tempered, judgmental, emotionless, narrow-minded, negative, evil, rational
Appearance Slender rat, grey fur, thick black eyebrows, goatee, green demonic eyes, red tunic over a pink shirt, pink-purple-and-black cloak, square gold pendant, barefoot
Occupation Rat of the Thornbush
Alignment Bad
Affiliations Don Bluth Villains
Goal To kill Nicodemus (succeeded) To pressure the rats into staying in the rosebush with him (failed)
To obtain the stone that was given to Mrs. Brisby by Nicodemus in order to gain power as the leader of the rats (failed)
Home The Rose Bush
Allies Sullivan (formerly),
Minions Sullivan
Enemies Mrs. Brisby, Justin, the rats, Sullivan, Mr. Ages, Council Rat, Nicodemus
Likes Power, Justin
Dislikes Nicodemus
Powers and abilities
Weapons Sword
Fate Gets stabbed in the back with Sullivan's dagger and falls to his death into the mud
Quote "He wanted to destroy everything. I've learned this much: take what you can when you can!" (his last words)
"No taste for blood, eh? They've taken the animal out of you."

Jenner is a major character in the 1982 animated adaptation of the Newbery Award-winning children's novel Mrs. Brisby and the Rats of NIMH, known as The Secret of NIMH. He is a power-hungry and evil rat of NIMH who betrayed his own kind due to his strong desire to remain in the rose bush, rather than leave to a better life in Thorn Valley, as promised by the elder leader; Nicodemus.


Jenner was one of many rats freed by Jonathan Brisby from NIMH. However, quite a few mice and rats died in the process of escaping. The survivors then moved into the Rose Bush which served as their home from then on. It is unclear about Jenner's movements prior to the film.

Role in the film

The Secret of NIMH

Jenner first meets Mrs. Brisby when she comes to the rats to ask for help moving her home. Jenner concocts a plan on the spot to use this as an opportunity to get rid of Nicodemus; the leader of the rats whom he openly disagrees with. He immediately voices his support to help move the Brisby home under the impression that it would honor the late Jonathan Brisby. Mrs. Brisby was uneasy in Jenner's presence but thanked him anyway.

As Nicodemus and Mrs. Brisby are leaving for their boat ride, Jenner carefully explains his plan to his confidant Sullivan; to sabotage the operation by cutting the ropes that will be used to lift and move the Brisby home in the hopes that it will crush Nicodemus. Sullivan expresses reluctance to taking such a risk and when he asks what to do about Justin; the head of the rat guards, Jenner simply replies "Leave him to me."

During the moving of the Brisby home, Jenner and Sullivan stand ready to cut the ropes. The cement block house comes to hover directly above Nicodemus and Jenner cuts one of the lines. Sullivan decides to take no part in cutting the ropes after having second thoughts about killing Nicodemus. Furious, Jenner rushes forward and cuts the rope himself, dropping the Brisby home, and killing Nicodemus.

With Nicodemus dead and the rats fell into grief, Jenner uses the situation to declare himself as the new leader and persuade the others to return to the rose bush. Mrs. Brisby arrives during his speech and frantically warns the rats that NIMH will arrive in the morning to destroy the rose bush and any rats living within. Jenner attempts to discredit her saying she has become hysterical, but the rats believe her and decide they must leave. Enraged by her meddling, he attacks her with the intention of killing her. Sullivan alerts Justin to the attack, causing Justin to throw himself between Jenner and Brisby. As Brisby recovers from the initial violence, Jenner spots the necklace of power given to her by Nicodemus and moves to attack her again, desiring the magical item for himself. Justin tries to stop him, but he is thrown aside and wounded by Jenner. Jenner tackles Brisby as she's running away and violently manhandles her trying to get the necklace. Justin comes to her aid and the two rats engage in a sword fight right after Jenner slashes Sullivan across the stomach, mortally wounding him.

While they are dueling, Justin (having been fully aware of Jenner's growing resentment and animosity toward Nicodemus, coupled with having seen Jenner fly into a homicidal rage, pushing Mr. Ages aside and attacking Mrs. Brisby to steal the Stone) correctly deduces that Jenner must have intentionally killed Nicodemus. Jenner does not even attempt to deny this, openly admitting to Justin that he killed Nicodemus, stating "I've learned this much; take what you can, when you can!" and only stops fighting when he is stabbed in the stomach by Justin. As Justin makes his announcement to the colony that they were going to leave the rose bush, Jenner sneaks up behind him atop a large stone and prepares to kill him from behind while Sullivan, who is dying, takes out a dagger. Mrs. Brisby gasps in terror and points up towards Jenner to warn Justin. Before Jenner can attack, however, Sullivan delivers the fatal blow to the nefarious rat, throwing his dagger which strikes Jenner in the back, causing him to fall over the stone to his death.

The Secret of NIMH 2: Timmy to the Rescue

Strangely, Jenner's existence is never acknowledged again in the sequel. 



  • Jenner was voiced by actor Paul Shenar, who portrayed the Bolivian drug lord Alejandro Sosa (Scarface, 1983) and womanizer Alexander Cross (The Mask of Alexander Cross, 1977)
  • It is quite possible that the performance enhancers given to the Rats of NIMH caused Jenner to become prone to aggressive behavior and possibly drove him insane as a side-effect. The side-effects could have also disrupted his brain chemistry and cause him to be dominating over others, hence his power-hunger and disregard for others.
    • There is evidence of this theory as Jenner seems to have a murderous solution to every problem as he suggests to the Council that the Rats of NIMH declare war on human beings. He also killed Nicodemus as his solution of staying in the Rose Bush and seems to blatantly insult those he disagrees with.
    • If this is the case, then the drug's side-effect must have a small percentage in statistics as none of the other Rats of NIMH have displayed this aggressive, homicidal behavior.
    • If this is indeed true, then Jenner could possibly be the only Rat of NIMH to be affected by this small percentage.
    • This theory is evidenced by Martin Brisby in the sequel, who also experiences similar effects.
  • In the graphic novels, Jenner plotted to have revenge on Mrs. Brisby and Justin after Dragon the Cat found him outside the Farm.
  • Jenner is often considered one of the most, if not the most, iconic and popular villains in the Don Bluth filmography.

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