Not sure how many people know, but if you go back to Squid Coast after beating it, there's an obsidian chest in a secret room past the first Skeleton. : r/MinecraftDungeons
EPONYMOUS SQUID EASTER EGG! Squid Coast Achievement & All Secrets Revealed in Minecraft Dungeons - YouTube
Minecraft Dungeons Secrets and Chests Location - How to unlock the secret cow level, Dingy Jungle, and Lower Temple | VG247
Minecraft Dungeons Secrets and Chests Location - How to unlock the secret cow level, Dingy Jungle, and Lower Temple | VG247
A Cry For Heroes (Squid Coast) Mission Walkthrough Minecraft Dungeons : r/ MinecraftDungeons
I Found This In Squid Coast. It Makes Mooshroom Sounds Along With Some Smoke when Pressed. Is This Some Kind Of Easter Egg Or A Secret? : r/ MinecraftDungeons
The Eponymous Squid Achievement in Minecraft Dungeons | XboxAchievements.com