His theme is Super Metroid OST - Item Room.
The Abstract Spy is a normal BLU Spy whose twisted body is missing the lower half of his torso. The upper half of his torso is bloated to resemble a semi-vague shape of a bell. His head is slightly smaller than that of the average Spy.
Personality and Behavior
True to his name, Abstract Spy is not so easily understood due to his strange appearance and mannerisms.
Rather than socialize normally, he is a silent individual and prefers to scare people with his weirdness. Apparently Abstract Spy is assumed to understand a Pyro's muffled language by his being able to speak it, which he uses to his advantage in creeping people out.
How he does this usually is to simply approach a person, make his head twitch, and speak Pyro. So far, Abstract Spy has managed to scare a Scout, though it is unknown if this method would work on other humans or Freaks like himself.
Powers and Abilities
Abstract Spy is capable of acting weird, and can achieve this either by warping his appearance (which presumably led to his current name), and speaking Pyro.
And because he has no legs to walk on, Abstract Spy relies on levitating himself to get to places he wants to go to.
Faults and Weaknesses
Abstract Spy's weaknesses are currently unknown, though he is helpless on his own without his legs and is assumed to be as weak as a normal Spy.