"Well, if it isn't Captain Clip-On. Guess who almost filed for unemployment today?"
- Gerald speaking to and about Billy Peltzer
Hopkins is a butt-kissing slime of a man, somewhat ambitious, selfish, very greedy and opportunistic person who shares a good relationship with Roland Corben, the current elderly (and possibly deceased) bank manager, but he really is just trying to grab his trust so the bank will be handed over to him after Corben's retirement. There is a rivalry between him and Billy Peltzer.
Hopkins first appears when Barney, Billy's dog, leaps out at Mrs. Ruby Deagle from under the desk in the bank. Both Corben and Hopkins are spiteful to Billy about this and take the over-reactive lying lady to first aid to comfort her.
He next meets Billy at Dorry's Tavern where he jokes around and bullies Billy, admitting proudly that he would've had Billy fired straight away without hesitation if the bank was his. As he continues to snipe at Billy with his sneery, cheesy comments, Kate reveals herself to be a daily evening waitress (except for Thursdays) and Hopkins attempts to ask her out. But Kate does not find him impressive, nor does she even like him. To Billy's pleasure, she refuses.
In a deleted (but most likely canon) scene, it it revealed that during the Gremlin rampage; he locked himself into the vault of the bank and despite Billy talking to him as he, Kate and Gizmo are inside the bank, Gerald doesn't want to come out so the trio just leave him there, deciding to pick him up later. He also seems to have lost his mind during this scene.
After the Gremlin attack Gerald was probably institutionalised for losing his sanity during the attack, leaving the bank to receive less corrupt management and the poor more time to pay off their debts (such as Mrs. Harris).