Phase 1 - Zombies, Dogs and Keepers
Phase 2 - Zombies, Dogs, Keepers, Panzer and New Cthulhu summoning skull attack
Phase 3 - Zombies, Dogs, Keepers, HVT Panzer and New Cthulhu summoning skull attack

How to kill - In order to hurt Cthulhu you must fill the book up with souls. These souls are collected by killing the keepers

Tips
Tip 1 - Cthulhu Wipe attack
- When Cthulhu jumps off ground and starts flying. He is about to use his Wipe attack. You must hide behind rock to stay alive

Tip 2 - Cthulhu asteroid fling attack
- When Cthulhu extends his arm out above you he will start throwing asteroids through a portal from sky at you. To avoid this you must simply keep running around the boss arena. If you stay still asteroid
will cause damage, if running steroid will miss

Top 3 - Best loadout for boss fight is
- Staff Of Dark Aether
- Aethergat / Ray gun Howl Akimbo
- Ppsh-42 / Mg42