Megasephalon

Megasephalons are mini-bosses that can only be found in Variation 3 Shipwrecks in the Abyss. Each Megasephalon appears as a Giant Squid, guarding the treasure chest in the room it spawns in. Upon death, they drop the key needed to open the chest. They are incredibly resistant to damage, so killing them will test patience in new players.

Behaviour
Megasephalons spawn passive at first, dealing no damage to the player on contact. However, when attacked, they turn hostile at the player, trapping them in the room they spawn in by barring the doors, making escape impossible until either the player dies or the Megasephalon dies. They hurt the player by either attempting to ram them or by swinging their tentacles. Their speed and attack pauses increment as they lose HP.