The kalack gland was a gland in Sheyangs located just above the stomach. It collects special enzymes and chemicals from the body and mixes them into a thick bile that ignites into intense flame when exposed to oxygen. Through a process similar to regurgitation, Sheyangs can spit this bile and produce a fireball.
As a Sheyang ages, the kalack gland becomes less efficient, and older Sheyangs often have trouble producing flame.
If Sheyang is shot by a pulse weapon when preparing to expel flame, the bile in the kalack gland will ignite and cause an intense explosion.