You won't create any Food tokens
Creatures are Magic s ultimate strategic resource, offering massive utility even compared to other permanents: they can attack, block, be sacrificed, hold enchantments and equipment, tap to pay for costs, provide a target for friendly effects, and so on
Umbris gets to exile cards from opponents decks whenever it or another Nightmare or Horror enters the battlefield
Since many rats care about the number of rats you have, cards like Pack Rat, Ogre Chitterlord and Vren, the Relentless are enablers and payoffs for the strategy, creating rats that grow in sequence with one another
And, crucially, for all practical purposes Event A never happened
However, if you gift a card (letting your opponent draw a card), you get three target creatures instead