ThunderCats

Lion-O's Anointment Final Day: The Trial of Evil (1x61)

Air date: Dec 16, 1985

Finally, to prove that Lion-O is worthy to be the Lord of the Thundercats, he must defeat his worst enemy. Mumm-Ra. He manages to find a way into Mumm-Ra's tomb, and defeats him by throwing his coffin into the evil cauldrum. This is the first time that Lion-O really defeats Mumm-Ra.