The TzRek-Jad (translated as Baby Fire Elemental) is a pet that can be obtained via Soul Wars. Players need 99 Summoning, 99 Slayer, 100 zeal points and a fire cape (which will be lost) to obtain it from Nomad or Zimberfizz. He apparently has a chew toy named Mr. Squeekles. Conversations with the TzRek-Jad seem to indicate that this pet should grow to be a TzTok-Jad and artwork (see below) seems to confirm this.
This pet doesn't need to be fed and will not run away.
Young Obsidian Elemental
TzRek-Concept art for the original design of the pet