In one of the five or six elite bits in the comic’s new HBO special, “Live at the Palace,” the funniest and most fully realized comedy hour so far this year, Fleming puts together an absurdly specific portrait of this person: mustache, thick thighs, under the delusion he’s the life of the party at weddings. Fleming’s friends insist he’s great. “You’ve got to meet Thomas,” they say. “He is so fun. He wears a kooky sock.”