Larry is an ICE program and Mako's goodtime boy.
While hacking a Horizon facility in "A Home After A Wake", Mako encounters Larry and copies his actions until Larry is so confused he thinks he's Mako. Afterwards Mako finds himself catching glimpses of "himself" through the Mesh, which turns out to be Larry hitching a ride on his brain. When the Chime leave Counterweight, Mako is hacked and possessed by Larry. When Larry encounters Righteousness it convinces him to settle down and cooperate.
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Larry dies protecting Mako's brain during the fighting against Rigour.
In his first appearance he looks like a stereotypical lumberjack. In subsequent appearances he looks like a mirrored and palette swapped version of Mako.