The Slither Pit is a Serpentine battle, in line with the snakes' warlike culture, which has two or more Serpentine fighting each other in a gladiatorial-style arena.
The events are used as a means of settling disputes, determining Serpentine leadership, and general celebration or entertainment. There are no rules beyond what the ringleader decides, and many arenas have lever-activated devices that can make battles more interesting and add more possibilities and outcomes to battles.
Hypnobrai Tomb Arena
The Hypnobrai Tomb's Slither Pits were conducted in a large section of the first floor largely devoid of icicles and other obstacles. The arena was only loosely connected to the surrounding floor by unknown mechanisms, leaving a small gap around the edge. The referee observed matches from atop an icy ledge ringed by a low wall dotted with spikes, giving it the appearance of a toothy lower jaw. There were no other seats or bleachers, leaving spectators to stand around the edges of the arena. An icy archway was present on one side of the arena, acting as a formal entrance-way for combatants. A pair of levers present on the referee's ledge activated different effects in the arena. One lever allowed for the raising and lowering of a rack of weapons suspended over the arena. The other—identified as the "Sidewinder"—caused the arena to tilt back and forth, possibly shaking the combatants' footing.
The Lost City of Ouroboros had a larger, more elaborate Slither Pit arena than the one seen in the Hypnobrai Tomb. Resembling an ancient Colosseum or a modern sports stadium, it had several gates and entrances through which spectators and combatants alike could access the arena. It also featured a number of bleachers around its edge, with enough room to seat the entire Serpentine army. The arena floor displayed a large, slightly raised spiral made of rocks, and it was overseen by a large statue of The Great Devourer, which was thought to be imprisoned in the city. The statue had a staircase built into its back, allowing access to a platform within its mouth. Its four main fangs had holes carved into them where the Fangblades could be placed. The statue was flanked by smaller snake statues which leaked streams of venom from their mouths. Like the Hypnobrai Tomb's arena, the Ouroboros Slither Pit had several gimmicks built in, which could be activated with the use of levers at the foot of the Devourer's statue. One lever caused spikes to emerge from the spiral design on the arena's floor, while the other caused it to tilt from side to side.
When the Serpentine built an underground fortress to conceal their movements from the Ninja, they built a Slither Pit arena at the very bottom. It lacked seats or even a defined referee position, with match overseers positioning themselves near the gimmick-activating lever instead. Unlike other Slither Pit arenas, it appeared to feature a speaker system, which projected the referee's voice when they spoke into a microphone. A small acid pool was present at the center of the arena, featuring a pedestal that bore a golden statuette with slots for the Fangblades. The fortress' Slither Pit arena had a single lever. When pulled, a ring of symbols spun around the outer edge of the arena, and whichever symbol was highlighted determined the change to the arena for that match. The only one shown was the "Vat of Venom," where the arena floor retracted to expose a series of narrow walkways over a pool of acid.
Yang Tavern Arena
Besides Serpentine, the Yang Tavern arena is often used by Skulkin and humans. Due to a lack of referee position, they stand inside the arena to observe matches. The spectators are seated in one of the tables and can be served juice similar to the appearance of Snogfruit Punch.