The Ictacular Grunflax is a Maxis made creature, present in the final game. It first appeared in the Creature Creator, having many "Pomp pom" parts in it's back.
The Ictacular Grunflax is a carnivore not very adept at fighting. They can bite their preys weakily. Also, they can charge and stun preys, and are capable of striking them with their hands.
Ictacular Grunflax are capable of singing when socializing, but are easily outsmarted. They can also pose with their primate graspers, but they are most adept at dancing.
The creature itself wasn't heavily changed from it's Creature Creator version, only losing the "Pom pom" parts from it's back.