Crypt Skeleton is unique enemy for Hidden Crypt dungeon. You can only reach it if you have access to the Robert's hideout.
Strategy[]
Enemy initially will hide undergrounds and reveal itself when up close, you can see ground being unearthed. Enemy has similar abilities to Skeleton Knight and such have same strategy approach. It has basic swing when up close and ground slam that is followed up with a shockwave.
Weakness[]
It's affected by knockback just like all giant skeleton enemies. When hitting the enemy, it will get pushed back.