This clever recursion engine relies on fueling a tight loop with the massive mana output of Selvala, Heart of the Wilds, whose tap ability scales off your largest creature's power to easily cover activation costs. Phantom Train acts as a vital outlet by letting you sacrifice your key permanents into it, turning the Vehicle into a creature while clearing the way. You then leverage the recursion ability of Slimefoot and Squee to pull both Selvala and Slimefoot and Squee itself right back from the graveyard to the battlefield. Finally, the Saproling token created by Slimefoot and Squee upon entry provides the fresh sacrifice fodder needed to keep the cycle spinning infinitely, rounding out the loop with the passive presence of Dragonlord Kolaghan watching from the command zone or library.