Tiny is a huge troll, and partner of Large, a slender elf, co-owing their gym. He was intended to fight K-O in a semi-pro fighting match, but thanks to a failed drug test was replaced by Pug for a run. 

☀Tiny punched Caber, knocking him out cold, after Caber attempted to use magic on him.  Was infected by nanites.
It could be speculated that Tiny was a good person before being infected with nanites, to the runners, this appeared to be the case. The runners intended to clear Tiny's name after the fight. This is why there was a jar of Pug's urine in Blowback's van during the Urinacorn incident.