I'm mostly writing because I saw someone say 'bandits'. No! Bad DM! Bandits are boring. They walk up, take some of your money, and leave you alone, because they are rational creatures that don't want to risk death. Goblins are fun little murder demons with sharp pointy teeth. THAT'S interesting. There's a bunch of different ways you can go with it, too. My goblins are sort of the seedy underbelly of faerie and chaos, closely related to things that go bump in the night (mental note: find a way to use bugbears). But those don't have to be your goblins. Maybe yours speak backwards and walk on ceilings. Maybe yours are actually plants. Maybe yours steal babies to feed to bugbears. But that's all more fun than "Give me your wallet."