In Shrek, Thelonious has intelligence he is first seen when Farquaad wants to choose a princess he wants him to pick number 3 which he had two fingers and later at Fiona's wedding.
In the short, he sings with Gingy.
In Shrek 4-D
In the short, Thelonious kidnaps Princess Fiona. In the near end, he redeems himself by betraying Lord Farquaad's ghost and rescuing the characters from Fairy Falls, then he presumably lived in new life of Far Far Away.
He seems to be not as smart as the others of Farquaad's men. Thelonious is cunning, arrogant, treacherous, resentful, bitter, cruel, harsh, scornful, traitorous, objectionable, emotionless, loathsome, uncaring, nasty, violent, obnoxious, impertinent, dangerous, sinful, vain, sly, noble, ingenious, outlandish, manipulative, uncompromising, contemptuous, duplicitous, honorable, sneaky, tenacious, hard-working, punctilious, envious, loyal, organized, naughty, insincere, opportunistic, ungenerous, and snarky.
He is tall, slender, and muscular, he has glowing green eyes, he wears a gray suit with a darker grey vest, gloves and shoes, and a black hood. His true face is never seen.