Heliod triggers, putting a +1/+1 counter on Herd Baloth.
Herd Baloth triggers, creating a creature token and an artifact token.
When the artifact token enters the battlefield, Teething Wurmlet triggers, causing you to gain life.
Repeat from step 2.
This elegant loop begins the moment you trigger Heliod, Sun-Crowned, turning any initial life gain into a +1/+1 counter placed upon Herd Baloth. That counter triggers Herd Baloth to spawn a 4/4 green Beast token, which conveniently counts as an artifact entering under your control thanks to Peregrin Took's replacement effect turning any token creation into those tokens plus an extra Food token. Teething Wurmlet watches these artifacts arrive and rewards each one by granting you a life, which in turn restarts Heliod, Sun-Crowned's trigger to keep the entire cycle spinning indefinitely.