ThunderCats (1985)

S1E32 Return of the Driller

The Driller, Mumm-Ra's loyal minion who previously captured Panthro in "Spitting Image," is back to assist his master. This time, he's tasked with boring a hole from the Cats' Lair to the Acid Lake, enabling the corrosive liquid to seep in and erode their home. Meanwhile, the Thundercats embark on a quest to locate the sole substance capable of neutralizing the acid threat.