Mr. Gladly is the teacher of Taylor Hebert's World Issues class at Brockton Bay High School.
Prior to the events of Worm, Mr. Gladly was the 'cool' teacher at Winslow High, known for assigning group work, insisting his students call him "Mr. G" and allowing the students to get away with things. Taylor hated him, as this behavior allowed the bullying and exclusion she was experiencing to continue inside the classroom.
Mr. Gladly is described as short, gregarious and young-looking enough to be mistaken for a high school student.
He struck Taylor as as one of the ‘popular’ kids who had become a teacher. She speculated that he probably thought he was everyone’s favorite, and wondered whether it would it shatter his self image to realize she disagreed.
He was "the sort of teacher who tried to be friends with his students, the sort who went by “Mr. G” instead of Mr. Gladly ... gave lots of group work so others could hang out with their friends in class, and had ‘fun’ assignments like mock trials."
Gladly would chat with a bunch of the more social members of his class afterwards, ending his classes slightly early.
He was especially animated when talking about parahumans and "for once, the class was listening".
Mr. Gladly offered his help to Taylor to attempt to resolve the bullying situation in 2.3. Following her outright refusal, Mr. Gladly ignores all further assaults.
Mr. Gladly's last appearance was as a civilian in an emergency shelter during Leviathan's attack on Brockton Bay. He is presumed dead following the events of this chapter, with possible confirmation in a post by White Fairy in Interlude 19.