Shilgengar, Sire of Famine acts as our engine by letting us sacrifice a creature to churn out a Blood token, but the real alchemy here happens when Chatterfang, Squirrel General joins the laboratory. Thanks to Chatterfang's replacement effect, every single Blood token Shilgengar creates is accompanied by a matching 1/1 green Squirrel creature token. We can then turn right back around and feed those very same Squirrels back into Shilgengar to keep the cycle spinning, generating an infinite storm of artifacts, creature deaths, and enters-the-battlefield triggers.