|First appearance||"The Silence of the Clamps" (6ACV14)|
|Voiced by||Phil LaMarr|
After breaking into the Donbot's eldest daughter's wedding party in Long Long Island, Bender witnessed a crime against Calculon carried out by the Donbot and his Robot Mafia partners. Once he had returned to the Planet Express headquarters, Bender saw Robot Stack state on television that the EBI was offering anyone with information about the crime a fifty-dollar reward. At Robot Stack's office in an EBI building, Bender told Robot Stack what he had seen in Long Long Island. Robot Stack said that it was not enough to convict the Donbot and that Bender would have to testify. Bender was not given the reward. Because the Donbot was found not guilty in Battery Park Integrated Circuit Court, Robot Stack helped the endangered Bender leave the Planet Express headquarters in an EBI spaceship and hide him as a chef at Family Bros. Pizza. Following the killing of Billy West, who was believed to be Bender, on the Moon by another daughter of the Donbot's, Bella, which made the Robot Mafia stop hunting Bender down, Bender was free to resume his normal life.
- Robot Stack is a reference to actor Robert Stack, who played the role of a Prohibition agent, Eliot Ness, in the hit television series The Untouchables.
- Stack is also the name of a data structure commonly used in computer programming.
- The name Robot Stack is given away by the door of his office.
Robot Stack: I enjoyed your story. [Robot Stack presses a button on the voice recorder.] Especially the tasteful love scene. [Robot Stack stands up.] But it's not enough to convict the Donbot. You'll have to testify... In open court.
[Robot Stack approaches Bender.]
Bender: No. No! Can I have another fifty dollars?
Robot Stack: No.
Robot Stack: Don't be scared, Bender. We're putting you in the witness relocation programme. [Bender uncovers his eyes.] You'll be given a new identity, a new place to live, and this iPod. [Robot Stack grabs an iPod from his right pocket and hands it to Bender.] I don't want it anymore.
[Bender looks surprised and somewhat happier.]
Bender: So I gotta hide forever?!
Robot Stack: No. Just until the Robot Mafia finds and kills you. [Fry looks shocked. Robot Stack looks at him.] They're pretty good at that.