The leader of the gang is Henry Bowers, an extremely violent bully who threatened the lives of the members of the Losers’ Club and got into physical and verbal altercations with the group on multiple occasions throughout the first film, including a huge rock fight.
Just as the Losers’ Club are the heroes of IT, the Bowers Gang are the villains.
This group of teens is slightly older than the Losers’ Club and spends the majority of its time tormenting the citizens of Derry, the Losers’ Club in particular.