"My Valentine Ghoul" in the forty-sixth episode of Darkwing Duck.
Morgana Macawber and Darkwing Duck are having a romantic dinner when Darkwing starts talking about a case where diamonds are disappearing across the city. Morgana wants to help but Darkwing refuses and tells her she will mess things up and get in the way. This infuriates Morgana and she starts throwing spells at Darkwing and he has to dodge them.
Meanwhile, it is revealed that Negaduck is behind the diamond disappearances and as he is stealing another diamond, he sees the commotion from the direction Morgana and Darkwing were having their date. He goes to investigate. Darkwing slips up and lets Morgana think that he does not trust her since she used to be a criminal and she tells him that they are through. Negaduck sees this and believes that he can use this to his advantage and he starts to court Morgana.
Gosalyn witnesses the fight and is determined to help her dad win back Morgana and enlists the help of Eek and Squeak. Negaduck shows up at Morgana's house and tells her that he is reformed and that he must trust her and plays up on her sympathy. She starts to believe him when Darkwing comes in. Darkwing refuses to believe him and begs Morgana to go on a date with him for Valentine's Day. Negaduck plays on her sympathy and convinces them to take him on the date too. They go to the local carnival together and Negaduck causes mayhem without Morgana seeing him. He fires an arrow at Darkwing in the Tunnel of Love and Morgana doesn't see it and it pins Darkwing to a giant heart. When she exits the tunnel, Negaduck tells her that Darkwing went off to solve a crime without her because he didn't trust her. This really infuriates her and they leave. Gosalyn sees this and knows that she must do something.
Eek, Squeak, and Archie take Gosalyn to a magic spell book to find a love potion. They concoct one and wait for everyone to return. Morgana and Negaduck get back first and Negaduck tries to woo her. Darkwing shows up and Gosalyn sprays him with the love potion by accident. Darkwing sees Negaduck first and thinks that he is his best buddy and will do anything for him. Negaduck tells him to jump off a cliff which he does. When Darkwing gets back, the potion wears off and he and Negaduck start to fight. Morgana tries to zap Negaduck and accidentally hits Darkwing and then herself. Negaduck takes her away and Gosalyn unfreezes her dad. Negaduck frees Morgana and attempts to get her to help him with his crime spree. She refuses and tries to zap him. He covers her in chocolate and just then Darkwing shows up and Negaduck covers him in chocolate too.
Gosalyn, Eek, and Squeak come into the fray and try to help but she falls and they get sprayed with the love potion. She falls for Negaduck along with Eek and Squeak. Darkwing frees himself and Morgana and tries to stop Negaduck. Gosalyn attacks Darkwing and uses Negaduck's frosting on Darkwing and Morgana. Then the potion wears off and Negaduck squirts her with the frosting too. It turns out the frosting is highly flammable and Negaduck tries to fry them. Morgana gets the rest of the love potion and fires it at Negaduck from Darkwing's gas gun. It causes Negaduck to fall for Morgana and she hits him into the machinery and he gets boxed up. Darkwing and Morgana return to their date but wind up fighting once again.
- "Nice shooting, Annie Oakley. With enemies like you, who needs friends?"
- — Negaduck on Morgana's aim.
- Morgana: You won't believe it, Negaduck has given up his evil ways.
- Darkwing: You're right. I don't believe it.
- Negaduck: Oh, but it's true. I've started my own company, Negasweets. I make Valentine candy.
- Darkwing: Like what? Chocolate-covered grenades?
- Morgana: Care for a jawbreaker, sweetums?
- Negaduck: Ooh, why thank you...
- Morgana: One broken jaw, coming up!
- Morgana: Negaduck, my little honeywumpus.
- Darkwing: Hey, I'm supposed to be your little honeywumpus!
- "This carnival's just a bunch of freaks, creeps, and misfits. Ah, just like my last family reunion!"
- — Morgana Macawber.
- Darkwing: (under control of the love potion) Aw, what's the problem, Neggis? Is there anything I can do for you?
- Negaduck: Yeah. Go jump off a cliff.
- Darkwing: Why yes. Anything for you, Neg-Meister.
- (Darkwing jumps out of the window and races to a cliff and starts falling.)
- Darkwing: Geronimo!!!
- Gosalyn: Oh bummer.
- Negaduck: And to think, after all this time, all I had to do was ask.
- When Darkwing and Morgana are riding a boat in the Tunnel of Love, Negaduck gets on a cupid statue and pulls back on the bow to fire the arrow at Darkwing. When they first show the scene, the bow in cupid's right hand and in the next scene, it's in the left.
- When Negaduck is chipping Morgana out of the ice block, he is wearing Darkwing's outfit.
- Negaduck's mouth doesn't move with his line "I don't know what you're trying to pull, Darkwing, but..."
- Negaduck cries in this episode; When he was faking it to gain Morgana's sympathy in order to woo her over after her fight with Darkwing in order to do crime. The other episode he cries is in "Jail Bird" (When he is defeated by Darkwing, Megavolt, Quackerjack, Bushroot, and Liquidator thanks to Megavolt, Quackerjack, Bushroot, and Liquidator’s weaknesses).
- The original name in the show bible for this episode is "A Darkwing Valentine".