In the web-choked ruins where the Spiderfang breed, the Arachnaroks are the oldest and holiest of terrors — spiders grown vast as fortress towers, their fangs slick with venom that can still the hearts of monsters. The grots do not tame them; they negotiate, in the way of small things living beside a volcano, and the shrines and howdahs they raise upon the great spiders' backs are offered as rent.
When an Arachnarok descends upon a battle-line, the Spiderfang read it as scripture in motion. Crewed by chanting shamans and grot archers, it stalks across the field on legs like siege-rams, plucking screaming warriors into its mandibles while the tribe swarms forward in its shadow. Armies that stand their ground discover that a wall of shields means very little to something that simply steps over it.