CAN I MAKE AN ACTOR BIGGER?

how do i make an actor bigger?like i want to make a boss in one of my games i'm making(mario's revenge)but i need to make the bullet bills he shoots alot bigger.how can i resize the actor.please reply.thanx.if i get a good reply and can make them bigger i will be able to finish my game and put it on the demo page so everyone can play it for free.