Source: Bestiary 3, pg(s). 32
A bandersnatch resembles a tawny, six-legged cat with wicked quills running the length of its body to the tip of its long, flexible tail. These quills can be flung at enemies with surprising accuracy. Anyone gazed by the bandersnatch's saucer-like, luminous eyes is captivated. A bandersnatch measures 50 feet in length, of which ten is tail, weighs 12,000 pounds, and moves with surprising grace and stealth for a creature of its size.
Bandersnatches are consummate hunters, hunting only the biggest or most cunning prey for sport, and pursue them without fear, rest, or remorse. They ambush prey while hidden by trees, savaging them, then running away again, gradually wearing prey down. If outmatched, the bandersnatch quickly withdraws, then picks up their trail and waits as pursuers separate from their allies to pick them off one by one.
Bandersnatches are native to the First World, and it is unknown if they were deliberately or accidentally released to the Material Plane by the fey. In the Material Plane, bandersnatches are extremely rare and make their lairs in forgotten ancient forests.
Each bandersnatch only mates at most twice per century. The couple separates as soon as they mate, and each litter contains one or two kittens. The newborns are fed by their mother and grow up to become lesser bandersnatches within a year. Bandersnatches live for at least a millennium.
Though no bandersnatch is ordinary, some are rarer than others: the confounding bandersnatch, whose quills and claws drip infectious madness; the frumious bandersnatch, who brims with rage so fierce it burns; the magicbane bandersnatch, who radiates an antimagic aura; and the primal bandersnatch, who has kept its tie to the First World.