I know that Furret are Normal-type, and when Deerling kicks one he does more damage than when he attacks other ways, so his kicks might be Fighting-type. And I've noticed that a lot of simple attacks like tackles or scratching don't hurt Golett at all, so maybe Golett is one of the types that are strong against Normal? Golett looks kind of like a human made of rock.

[Yup, he has a Ground/Ghost type.]