Trey Welsh is a character in Grand Theft Auto 2 and is the leader of The Zaibatsu Corporation in the Downtown District of Anywhere City (although his head looks identical to those of Red Valdez and Uno Carb). Welsh employs Claude Speed to initially stop an informant selling stories to the police, but continues to employ him. Welsh has Claude deliver drugs to four dealers around the city, blow up a Loonies controlled building, destroy the Yutes gang, rob a bank to get money and pay some men, destroying two Yakuza cars and to steal some used bank notes from bank vans. Claude eventually angers Welsh, Elmo (leader of the Loonies) and Johnny Zoo (leader of the Yakuza), but manages to kill all three.
His wife of five years is Petula Shoe. His police file claims that he is talented at illegal street racing, injecting people with drugs without them realising it and kidnapping, and that his excessive use of untested drugs has turned him into a "Dr. Jekyll style guinea pig". He is also known as "The Chemist", "Schizo" and "Speed".