This clever loop relies on Kiki-Jiki, Mirror Breaker and its ability to continually churn out fresh copies of Wormfang Drake. Each time a Wormfang Drake token enters the battlefield, its trigger exiles Kiki-Jiki, effectively tucking your goblin shaman away for safekeeping until you need him back. You then use Umbral Collar Zealot to instantly sacrifice that Wormfang Drake token, triggering its leave-the-battlefield effect to return Kiki-Jiki safely to the battlefield ready to repeat the process. Along the way, Umbral Collar Zealot's sacrifice outlet lets you continually filter your deck with surveil 1, while generating an infinite storm of enters-the-battlefield, leaves-the-battlefield, and death triggers.