Nubs. That's what he has.
Whatever you do, his horns always catch your attention, even when the words are spilling out of his mouth. Not that the words are ever NOT doing that, but still. Kankri's horns were like catnip to a cat in Cronus eyes. So each and every day when he ran into Kankri, he would just sit back, wait for Kankri to get lost in his own lectures, and stare at the two candycorn horns sprouting from his scalp.
It was true that his lectures were endless, but seeing as Kankri was the only person that actually listened to him, Cronus didn't mind. And if he was completely honest, there was something about the mutant.. That was a