| Hey, aren't you that plant lady, Poison Oaky?|
The Thinker was present when Luthor was given a tour of the Legion of Doom base. He later appeared at a bar in Central City laughing at something with Dr. Alchemy. He was sitting near the Tattooed Man and the Monocle during a meeting of the Legion of Doom a short time later.
The depicted subject bears the likeness of Thinker from the DC Comics; however, the DCAU character was never named on-screen, or otherwise. The title of this article is conjecture based on the character's likeness.
Clifford DeVoe was an unsuccessful Central City lawyer, until he met Professor Hartwell Jackson, a scientist that studied about people's thoughts and invented the Thinking Cap, a device able to control someone's mind and can read his/her thoughts. DeVoe decided to steal the Thinking Cap and gained psychic powers and decided to become the supervillain the Thinker, which led him to clash with the Flash and Justice League.
|Members of the Secret Society|
|Grodd • Lex Luthor|
|Clayface • Giganta • Killer Frost • Parasite • Sinestro • Shade|
|Angle Man • Atomic Skull • Bizarro • Black Mass • Blockbuster • Bloodsport • Cheetah • Copperhead • Crowbar • Devil Ray • Doctor Cyber • Doctor Destiny • Doctor Polaris • Doctor Spectro • Dummy • Electrocutioner • Evil Star • Fastball • Giganta • Gentleman Ghost • Goldface • Heatwave • Hellgrammite • Javelin • The Key • KGBeast • Killer Frost • Lady Lunar • Livewire • Major Disaster • Merlyn • Metallo • Mirror Master • Monocle • Neutron • Nightfall •Psycho-Pirate • Puppeteer • Puzzler • Queen Bee • Rampage • Shade • Shark • Silver Banshee • Sinestro • Sonar • Sportsmaster • Star Sapphire • Tala • Tattooed Man • Thinker • Top • Toyman • Tsukuri • Volcana • Weather Wizard|