|Real name:||Arthur Brown|
|Portrayed by:|| *Glenn Shadix
Arthur Brown was a young child prodigy with a promising life ahead of him, accomplishing many things and earning many awards throughout his life, including one for the creation of a successful little person football team. Eventually, he competed on a game show called Think, Thank, Thunk and was the reigning champion for twelve weeks until Yelena Klimanov defeated him. He threw a temper tantrum on live television, saying the show was rigged and prompted his mother to sue the show. The lawsuit was eventually dismissed, culminating in Artie going into hiding at his house in shame and anger, becoming extremely obese due to his lifetime supply of Kremelos, which was his consolation prize from the game. He turned his back on his future and devoted his life to revenge, obliviously wasting away his talents and his future.
In the episode Q&A, Cluemaster used his minions (his football team members) to capture Yelena, Ross Daren and Herbert Ziegler, making them all compete in a mockup version of Think, Thank, Thunk. He forced them to ask him questions; if he got them right he got a point, if he got them wrong, they got a point. 3 points won the game for that person; if they won, they were free, but if Cluemaster won, they got dunked in acid. Artie, indulging in his above-average knowledge, was sure of victory and easily outwitted the three and prepared to drown them in acid. Eventually, the Batman showed up, having tracked Artie to his headquarters, and challenged Artie to an 'all or nothing' round; one question of Batman's choice on any topic, with Artie releasing the hostages if he lost. With Artie confident in his victory, Batman asked Artie the only question that he didn't know: "Who is the Batman?" Cluemaster was so upset that he attacked Batman, again claiming that he had been cheated. He tried to expose Batman's identity, but was defeated when Batman tied up his legs, knocking Artie out with his own weight. His three hostages were freed unharmed after Artie was defeated.
He was later captured by the vigilante Rumor.
Artie was very smart and was proud of it, but this led him to being rather smug. He was also shown that he was spoiled by his mother, as he flew into a rage when he lost the game show. In fact, due to his obsessive nature, it seems any question he doesn't know the answer to causes him anger, believing that he knows everything. Believing he could never lose at anything, Arthur set himself up for a hard fall when he was younger, competing on a show he surely couldn't win forever. His obsessive nature led him to becoming very immature and irrational, abandoning his promising life altogether. As Batman pointed out, only his opponent, Yelena Klimanov, had gone on to achieve anything productive or admirable, regardless of who was the more intelligent one of the two of them.
- "Rumors" (cameo)
- Glenn Shadix (English)
- Naomi Kusumi (Japanese)
- Oliviero Corbetta (Italian)
- Stefan Fredrich (German)
- Cluemaster has got The Peter Pan Syndrome.
- His origin is completely different from the comics.
- His voice actor is dead.