Slaadi are beings of pure chaos, native to the outer plane of Limbo, vaguely resembling humanoid salamanders. There’s no good reason for them to be hanging out on the prime material plane, but being beings of pure chaos, they don’t need a good reason to be doing anything.
Slaadi come in a variety of colors, tied to their bizarre reproductive cycle. Red slaadi deposit eggs that hatch into slaad tadpoles (I think the writers missed a great opportunity by not calling them “slaadpoles”), which grow up into blue or green slaadi. Blue slaadi, in turn, infect victims with a bacteriophage that transforms them into red or green slaadi. Green slaadi are more powerful and intelligent than red and blue slaadi, and they eventually metamorphose into gray slaadi, which in turn can metamorphose into death slaadi by eating the corpses of other death slaadi.
Being aberrations, slaadi should behave—and fight—in ways that reflect their origin on the plane of chaos, a factor that has to be considered alongside their abilities and features. Slaadi are high-challenge monsters, so as tempting as it may be to ramp up the chaos they create by having the player characters encounter many of them at once, it can be deadly to throw more than one slaad at a party of low- or even intermediate-level PCs. Moreover, their ability to reproduce by turning humanoids into slaadi and slaad hosts can have exponential effects, so even one slaad is a threat that needs to be squelched pronto. (more…)