In Paul S. Kemp's early trilogy, the main antagonist known as the Sojourner has 4 slaadi henchmen that he refers to as his "children" named Azriim, Dolgan, Eleura and Serrin.
Chourst's inquisitiveness once drove him to visit Mechanus, although he barely survived the encounter; Primus himself showed up to deal with the slaad after he had worked enough mayhem and disorder on the orderly plane, and still seeks justice against Chourst.