On death, each Rock Scarab has a chance to drop a Scarab Shell, which is notable for being the only uncraftable shield in Roguelands.
The Rock Scarab is replaced by the Aberrant Rock Scarab on Challenge Level 1 and above. The Aberrant Rock Scarab has more health and damage than its lesser sibling, but otherwise behaves similarly to it.
The Scarab(s) will chase you with the worm AI, drop obstacles in the form of Scarab Eggs and only has one hit box, on it's head. It has invincibility frames so you cannot hit it multiple times in one attack, so fighting with ranged weapons and combat chips (Tech, Magic and Dexterity) are most efficient.
SpawningTo spawn a Rock Scarab you need to destroy Ores in the Hollow Caverns. After destroying Ore you have a chance to get a message from Lenny. When the third message appears, the Rock Scarab has spawned and you should probably run if you can't fight.
Before breaking the final rocks, make sure that you have full mana (if applicable) as he takes a lot of hits that do not include basic attacks, since it only has one segment and one hit box. During the fight, it's best to dash backward instead of going head on because of his spear-like head. Watching out for the eggs is easy if you continue to dash back and forth and lead him in a circle.