|Alias:||Supreme King Awesome Thunderpants, Oh Great Ruler of Terrenceania, Doggie|
|Family:|| Mac & Terrence's Mother (mother)
Red (imaginary friend)
Bloo (Mac's imaginary friend)
|First appearance:||"House of Bloo's"|
|Voiced by:||Tara Strong|
Terrence is a typical 13-year-old bully, the main antagonist of Foster's Home for Imaginary Friends, and the archenemy of Mac and Bloo. He has a mullet haircut, a bad case of acne on his face and wears a grunge style of plaid wool shirt, a black t-shirt underneath, blue jeans, and white sneakers.
Mac, Bloo, their friends, and everyone at Fosters despise Terrence and enjoy whatever misfortune befalls him, knowing full well he deserves it.
Terrence enjoys constantly bullying his younger brother Mac, and his biggest wish is for Mac and Bloo to never see each other again. In spite of his bullying attitude, he was seen watching a soap opera (The Loved and the Loveless) in "Berry Scary." He is also incredibly stupid, which makes him very easily outsmarted. In the pilot, he conspires with Duchess to get rid of Bloo permanently, but fails and is punished by being locked in the imaginary horse stables, where he is attacked by the unicorns, whom he had called "girly" earlier in the episode. Starting in "Beat with a Schtick", he appears with a different afro haircut. In "Eddie Monster", he meets Eduardo in a dumpster in the slums of the city and recruits him to fight in the Extremeasaur Battle circuit, but is caught when he brags to Mac about it and is later disqualified from the circut.
In "Duchess of Wails", Terrence tells Mac that because their mother cannot stand Duchess, whose next-door neighbors, the Applebees, have adopted, she plans to have their family move to Singapore, which Terrence mistakenly believes to be in Wisconsin. He even gets everyone at Foster's to help him keep Mac and Bloo from getting Duchess back into Foster's but fails when they learn about Mac moving and agree to take her back. Terrence also appears in "Infernal Slumber" where he attempts to wake up his and Mac's mother to show her Mac's friends being at their apartment and get Mac into trouble and never see his friends again, but Cheese jumps on and covers his face to keep him quiet and Eduardo ultimately knocks him out and when Terrence explains to his and Mac's mom about Mac's friends being over and that Mac never gave Bloo up, she does not believe him and grounds him.
- House of Bloo's
- Berry Scary
- Seeing Red
- Beat With a Schtick
- Eddie Monster
- Duchess of Wails
- A Lost Claus
- Infernal Slumber
- I Only Have Surprise for You (flashbacks)
- Goodbye To Bloo (cameo)
- He sounds like Kevin from Ed, Edd 'n Eddy, as they both are voiced by females using a deep voice.
- Tara Strong once said in an interview with voice actor Rob Paulsen that Terrence is her least favorite role she's done because it strained her vocal chords.