When Kitchen Finks dies, its persist ability triggers, returning Kitchen Finks from your graveyard to the battlefield with a -1/-1 counter on it.
When Kitchen Finks enters the battlefield, it triggers, causing you to gain 2 life.
Spider-Man triggers, putting a +1/+1 counter on Kitchen Finks.
Resolve the Shilgengar ability.
Repeat.
This clever loop centers around Shilgengar, Sire of Famine, which happily consumes your creatures to generate Blood tokens. When you feed Kitchen Finks to Shilgengar, persist brings the Finks right back to the battlefield with a -1/-1 counter, and its entry ability triggers to gain you 2 life. That sudden lifegain awakens Spider-Man, Peter Parker, whose triggered ability places a +1/+1 counter on Kitchen Finks. Thanks to the stack, this counter instantly annihilates the -1/-1 counter via state-based actions, leaving Kitchen Finks completely fresh and ready to be sacrificed to Shilgengar all over again.