A mysterious superhero shows up to the cul-de-sac and steals back the money Eddy got from his latest scam. Angered by his noble nature, Eddy vows to end his heroics by playing along.
Robbin' Ed provides examples of the following tropes:
- Audience Surrogate: Ed acts as this as he provides commentary during the hero and villain's first confrontation.
- Bad "Bad Acting": Eddy and Double D do this for their second (fake) scam in order to lure Captain Melonhead.Edd: Hold your horses! This butt's been used!
- Bag of Holding: The Thing-A-Majig is a tiny contraption that is able to dispense any desired object in a moment's notice.
- Breaking the Fourth Wall: While complaining about Eddy tricking the kids with his scam, Edd states that that's what they do in every show, and yet "not like this!".
- Call-Back: When Captain Melonhead makes his first appearance as a silhouette, Edd wonders if it's a bird. This prompts Eddy to ask if it has a quarter in its mouth, demonstrating that he still has a grudge on the bird that stole his quarter back in "Virt-Ed-Go."
- Crazy-Prepared: Captain Melonhead is shown to wear a second melon helmet should he lose his first helmet.Captain Melonhead: There's two halves to every melon, Professor Scam!Double D: That was clever.
- Cut Lex Luthor a Check: The Thing-A-Majig actually works, so the Eds could have simply auctioned it off for a hefty sum since all the kids clearly wanted it.
- Everybody Knew Already: While CM declares that he'll continue to keep the Cul-De-Sac safe, the kids refer to him by his real name and lose interest in the whole debacle.
- Evil Is Hammy: Eddy loves playing the supervillain. It actually works against him at one point: he spends so much time monologuing about how awesome his escape vehicle (a "bad to the bone, meaner than a junkyard dog, Professor Scam Flyer") is that it flies off before he can mount it.Eddy: Oops.
- Green Thumb: One of Captain Melonhead's attacks involves shooting acorns at his enemies that grow into full grown trees in seconds.
- Heel–Face Turn: Ed was always a good guy, but he betrays Professor Scam in the last minute to save his tub of gravy.
- Hostage Situation: Professor Scam gets the Captain to surrender by threatening to shoot Splinter with a garden hose.
- Minion with an F in Evil: Ed and Edd aren't very enthusiastic evil minions. Edd is guilty about torturing Jonny and Ed doesn't want his tub of gravy wasted.
- Mirthless Laughter: When Eddy orders his "henchmen" to laugh evilly, Edd does an unenthusiastic "mwahaha" and Ed outright sobs.
- New Powers as the Plot Demands: Out of nowhere, Eddy displays the ability to shoot dollar signs, which he calls his "Ray of Riches".Ed: The Ray of Riches will never penetrate the Force-Peel of Melon!
- "Oh, Crap!" Smile: Professor Scam gives a sheepish smile when his getaway vehicle floats away.
- Riding into the Sunset: Captain Melonhead and his arbor ally ride into the sunset as the episode ends.
- Shout-Out:
- The title and plot is based on Robin Hood.
- When first meeting Captain Melonhead, Double D and Ed state the introduction lines of Superman.
- Superhero Episode: Johnny and Plank become the scam busting heroes Captain Melonhead and Splinter the Wonderwood. Eddy plays along by becoming Professor Scam: a scam-obsessed criminal with money themed attacks.
- Underwear of Power: Eddy's Professor Scam costume includes a pair of tighty whiteys. He makes Ed and Edd wear these as well. They look ridiculous, which Edd complains about.
- Use Your Head: Melonhead's helmet can be used to deflect attacks or as a battering ram.
- Visual Pun: To get Double D to stop rambling, Eddy puts a sock in his mouth.
- Waxing Lyrical: Eddy describes his would-be escape vehicle as being "meaner than a junkyard dog."
- We Will Meet Again: Despite being defeated, Professor Scam vows to return like a bean burrito.
