The Fourth Floor Guardian of the Great Tomb of Nazarick. 
Unknown if golems have personalities or are purely constructs that follow orders.
Gargantua was first mentioned in Volume 1.
It is mentioned again in Volume 3's Epilogue.
Volume 4 is Gargantua's first appearance.
Web Novel Edit
Referred to as a "Tactical Siege Golem". Described as being part of YGGDRASIL and not an NPC created from scratch. Part of this not origin is Gargantua was written to be a Fourth Floor Guardian, however the golem could not be used for base defense and only for sieges. Due to storage reasons, the golem was just left in the bottom of the 4th Floors lake. 
Unlike other NPCs, there has been no mention of a personality or relationship with other NPCs. If this is due to being a golem or it's atypical origin has not been elaborated on.
- ↑ Volume 1 Epilogue: "the ultra-large golem Gargantua"
- ↑ Volume 4 Chapter 4: "Before his eyes was a massive statue hewn of stone, with a pair of arms and legs. Its sturdy, slab-like chest pulsed with red light, like a heartbeat. Its limbs were thick and stubby, and it looked almost adorable …well, it would have been, if it were not over thirty meters tall. This massive stone statue suddenly appeared from the forest."
- ↑ Volume 1 Chapter 2 The Meeting: "the Fourth Floor Guardian Gargantua"
- ↑ WN 6 The Meeting