JACK O'TOOLE. BtVS Demon/Monster/Villain.
A Sunnydale High student whose wrath Xander incurs in "The Zeppo" after he accidentally knocks over his potato chips while trying to catch a football. "I get my buddies together," he tells Xander, "we're gonna kick your ass till it's a brand-new shape." Later he talks about the encounter with Cordelia, who had witnessed it firsthand:
Xander: (glances at Jack) Why is it that I've come face-to-face with vampires, demons, the most hideous creatures Hell ever spit out, and I'm still afraid of a little bully like Jack O'Toole?
Cordelia: Because, unlike all those creatures that you've come face-to-face with, Jack actually noticed you were there.
Later in the episode Xander backs into O'Toole's (stolen) car and he threatens him with a knife:
Xander: Exactly. Look, I can cover the damages. I don't have insurance in the strictest sense of the word, but I have a little money. The
important thing is that we're alright and we can work this out like two reasonable...
Jack pulls out a very long hunting knife and holds it up.
Xander: ...frontiersmen.
Jack: (points the knife at Xander) Where do you want it?
Xander: What?
Jack: Where do you want it?
Xander: I'm fairly certain I don't want it at all, but, uh, thank you.
Lysette: (bored and impatient) Wow. Cool knife.
Xander gives her a look. She rolls her eyes and walks back to the car.
Xander: Yeah. Great knife. Although I think, uh, it may technically be a, a sword.
Jack: She's called 'Katie'.
Xander: You gave it a girl's name. How very serial killer of you. (turns to Lysette) Listen, I think we should be going.
Jack reaches around Xander with the knife and hooks it behind his ear, forcing Xander to look at him. Xander quakes with fear.
Jack: (jeeringly) Are you scared?
He traces the tip of the blade around Xander's neck and cheek.
Xander: (shakily) Would that make you happy?
Jack: (sneering) Your woman looking on, you can't stand up to me? Don't you feel pathetic?
After refusing to rat O'Toole out to a policeman, Xander becomes a reluctant member of O'Toole's gang, who he quickly learns are actually zombies who plan to blow up the high school, a plan that Xander single-handedly prevents while the rest of the Scooby Gang is preoccupied with The Sisterhood of Jhe's opening of The Hellmouth. He proves braver than O'Toole, who in a game of chicken disconnects the bomb just before it would have exploded:
Xander: I know what you're thinkin'. Can I get by him? Get up the stairs, out of the building, seconds ticking away... I don't love your chances.
Jack: Then you'll die, too.
Xander: (raises his eyebrows) Yeah, looks like. So I guess the question really is... who has less fear?
Jack: (tries to psyche Xander out) I'm not afraid to die. I'm already dead.
Xander: Yeah, but this is different. Being blowed up isn't walking around and drinking with your buddies dead. It's little bits being swept up by a janitor dead, and I don't think you're ready for that.
He's proven right when Jack makes a move for the door. Xander matches his move, and Jack realizes there's no way he can get out. They face each other from opposite sides of the bomb. Xander is oddly calm whereas Jack is clearly afraid.
Jack: Are you?
Xander: (glances at the bomb, smiles thinly) I like the quiet.
Fleeing the scene, O'Toole is eaten by Oz-as-werewolf (the next day he admits to feeling "oddly full").