I am a DM for the Tomb of Annihilation published adventure. My group will be exploring an abandoned mine near Fort Beluarian, so I wanted to create a level mini-dungeon for a party of five people.
Choosing the monsters randomly, I put a Gibbering Mouther in the dungeon. However, reading its Bite attack, I read that if the bitten creature drops to 0 hit points, it's absorbed into the Gibbering Mouther.
What does this mean? If the character drops to 0 HP from the attack, are they instantly killed because then they're absorbed into the creature?
Or does that character make death saving throws as normal, and if they pass, they're not absorbed? If so, can the character return to battle if healed?
Which one is it?