Depends, really. Sometimes I name them after the kind they are, or something. Like I call my Whooper Whoop-Whoop. Or I'll use something from the old language the Water Tribe used. Like Iqniq and Tunna and Orki. Iqniq means fire, and he's a fire type. Tunna and Orki are chubby, so their names mean 'Chubby' and 'Blubber'.