Encroaching Mycosynth is the clever linchpin here, turning every nonland permanent you control—including any Goblins you create—into an artifact in addition to its other types. This means that when Thermopod sacrifices a creature for red mana, Krenko, Baron of Tin Street sees an artifact hit the graveyard. By paying that exact mana back into Krenko's triggered ability, you replace the sacrificed creature with a fresh 1/1 Goblin token that immediately benefits from Encroaching Mycosynth's continuous typing, ready to be sacrificed right back to Thermopod for an infinite loop of death triggers and mana.