He's the junkman in Halloweentown. He lives in a messy cottage. Things that get lost in both the mortal world and Halloweentown ends up in Gort's cottage. He hates everyone and everything except his pet giant bug called Spot, which is the only thing that he shows kindness or love towards.
As a reversal, Gort feels complimented when someone says something that most people would consider insulting; Aggie described him as the meanest, dirtiest and all-around messiest person ever, something he felt was like being buttered up. Under the Grey Spell, he becomes a quiet and kind man who dislikes dirt. When Marnie kept switching him with "Apart" and "Trapa", he was left disorientated and disgusted with himself.
Anything lost in his house goes poof. In other words, it's gone forever.