Who is Richie Tozier from It and what is their importance?

Richie Tozier is a radio DJ who is the master of a hundred voices. Richie imitates people and creates character voices in order to entertain his listeners. Richie has always been a funny guy and has always had a mouth that tended to work before he could stop to think about what he is saying. This habit got him into trouble often as a child, especially when he would say things to Henry Bower, the local bully in his hometown of Derry. Richie has forgotten about Henry, but when Mike Hanlon calls and reminds him of a promise to return to Derry, Richie begins to remember. Not only does Richie remember Henry, but he remembers the friends he made the summer of 1958, the same friends he is returning to Derry to reunite with.