Be it grass, fruit, or beasts, whatever you eat, you have to live its part.

I can't say I'm familiar with the one called Golett, but if normal-type attacks aren't affecting it, it's probably a ghost type. Ah, though of course, just because the gym uses mostly normal types, doesn't mean they only have attacks of that type, so while ghosts are useful, you shouldn't rely on them to be simply immune to everything.