If you were looking for the normal game version go here: Shoggoth King eel of the Abyss.
Shoggoth is the main boss of Liv midnight mode. Once you get 30 silver coins and open the door you will get to fight Shoggoth, as soon as you walk through the doors they will attack.
Shoggoth acts the same as they do in the main game, but unlike the main game they can actually be killed this time.
The best way to beat Shoggoth is to dodge and attack him as he goes past, running away as needed to heal.
- Shoggoth was a pet snowflake eel Kira had while developing the game who passed away in 2018; he's a boss/npc as a memorial to him.
- Shoggoth is also the name of a well-known Lovecraftian creature, the invulnerability of shoggoth is well in-line with Lovecraftian horror. Here's more information on the topic: https://en.wikipedia.org/wiki/Shoggoth