The bone hooks that protrude from the back of a blue slaad's hands inflict a terrible transformative disease on humanoids wounded by them. This infection, called chaos phage, transforms its victim into a fully grown red slaad—or green slaad if the host was a spellcaster able to cast 3rd level spells or higher.

Almost as numerous as red slaadi, blue slaadi are muscular brutes with vicious blades extending from the backs of their claws. These claws carry a magical curse called chaos phage, which can transform victims into red or green slaadi. Blue slaadi accompany red slaadi and behave similarly. They innately know the signs of chaos phage and avoid slaying creatures that carry it or other slaad curses.

Death slaadi are suffused with energy from the Negative Energy Plane and exemplify evil's corruption of chaos, and they take sadistic pleasure in bringing harm to others. They propagate their race by dragooning mobs of red and blue slaadi and invading other planes. Humanoids who survive the incursion become incubators for new slaadi.

Slaad lords create death slaadi by infusing gray slaadi with a portion of their chaotic energy. When groups of slaadi act deliberately, death slaadi are often behind their designs.

Outside of Limbo, gray slaadi act as living extensions of the will of their masters, the death slaadi. A gray slaad journeys to the Material Plane on errands of doom, often taking humanoid form. A gray slaad learns how to master the use of a greatsword and imbue it with its own innate magic.

A gray slaad that eats the entire corpse of a dead death slaad instantly transforms into a death slaad.

Gray slaadi arise from green slaadi transformed by the Spawning Stone or slaad lords. They explore the planes, seeking Humanoid communities to invade near planar pathways.

Green slaadi are surprisingly intelligent and possess innate spellcasting ability. A green slaad can change its shape to appear as a humanoid. If it was born of a humanoid host, the slaad usually adopts its host's form.

At some unpredictable point in its existence, a green slaad unlocks the means to magically, instantly, and permanently transform itself into a gray slaad. Unlocking this knowledge can take years, even decades.

Green slaadi come into being when the propagation methods of red or blue slaadi affect certain creatures capable of casting spells of level 3 or higher. Green slaadi are more intelligent than their blue and red brethren and often direct their kin to portals where gray slaadi have identified Humanoid communities ripe for invasion.

When a red slaad claws a humanoid creature, it can inject an egg from a gland under one of its claws. The egg works its way into its host and gestates, eventually forming a slaad tadpole. Such a tadpole then eats its way out of the host's body, feeds on the host's remains, and then seeks any other fresh meat it can find. The tadpole transforms into a fully grown blue slaad-or green slaad if the host had the ability to cast 3rd level spells or higher-within 2d12 hours.

Red slaadi amass in vast throngs in Limbo. There they wrestle and croak-sing as they endlessly dismantle and rebuild islands of drifting planar matter. When they encounter non-slaadi, red slaadi seek to play with, telepathically converse with, or devour the other creatures. These whims change from moment to moment. Red slaadi instinctively avoid harming those bearing slaadi eggs, which red slaadi implant using their claws, or other slaad curses.

Slaad tadpoles are ravenous, newborn slaadi. They hatch from eggs implanted into living hosts by red slaadi, but they also appear in great numbers in Limbo and other chaotic realms. Under most conditions, a slaad tadpole transforms into a blue slaad—or a green slaad if its host was able to cast spells of level 3 or higher—within 2d12 hours of hatching.