It coughs up an orange

I feed the mimic Kirby, who just came back from the doctor

The Mimic puts up quite the fight, but it is no match for Kirby, the Devourer of Gods. As the Mimic is absorbed by Kirby, the pink puffball gains two extra eyes on each side of his face, as well as sharp teeth and a long, slimy tongue. The game has become Feed the Unholy Eldritch Abomination.

I feed the Unholy Eldritch Abomination (or UEA for short) a compass that seems to point everywhere but north.

It spits out a map with a missing compass rose.

I feed it fifty thousand Bazooka Joe comics.

The UEA learns what true friendship is, through the seemingly innocent tales of Joe and his gang. It decides to keep @Pug_With_Big_Weapons as a companion and now demands twice as much food for both of them.

I feed each of them with a set of magic beans.

Upon consumption, the magic beans grow into towering beanstalks. As the UEA's stomach is an infinite void, it is fine, but unfortunately, Pug is not. The stalk bursts out of their chest cavity, causing them immense pain. They pass out, and die hours later.

I feed Pug's withered corpse to the UEA.

UEA, being actually Kirby, can only have one power-up at a time. It spits out the Mimic and devours Pug's corpse, assuming humanoid-like features with pink skin and holding two Big Weapons in its arms.

I feed only the Mimic, with the 7 Chaos Emeralds.

It spontaneously combusts.

I come back to life and revive it, then train it for the olympics. It wins, and I feed it a chicken dinner.

It turns back into a mimic.

I feed it a mouse (the plastic computer kind)

Quote from FlamboyantFoxi >>

It turns back into a mimic.

I feed it a mouse (the plastic computer kind)

It spits out a fancy light-up gamer keyboard, complete with speakers.

I feed the mimic a french fry. Only one, though. I want to eat the rest.

Quote from The_DragonTamer

It spits out a fancy light-up gamer keyboard, complete with speakers.

I feed the mimic a french fry. Only one, though. I want to eat the rest.

 It wants more and steals your french fries and slaps you.

I feed it a banjo

The mimic emanates a quick and jaunty banjo tune.

I feed it a Fireball (whiskey).

The mimic thinks that you are actually casting Fireball and counterspells you (to no avail) as you shove the Whiskey down its gullet. It spits out an empty bottle.

I feed the mimic my hand.

It spits out your other hand. You are now missing the other hand, but at least you have the first one back!

I feed the mimic metal dice.

You roll them into his mouth, and all five of them land on Nat 20s, but no one is around to see them. So therefore, you are sad.

I feed the mimic my foot.

The mimic spits out your second hand. Certainly not a form of trading I’d like to do, but to each their own.

I feed it some toothpaste.

It gives you 4 gallons of tar.

I feed it a +7 Greatsword.

It spits it out and slays you with it, then steals the money you used to buy it.

I don't feed it. instead, I gift it a machine that summons any kind of food it wants on command, then teach it to speak Common and how to use the machine.

It tells the machine to feed it YOU.
I then come up and destroy the machine, and feed the mimic a simple apple.

the mimic eats and spits the core out at you i feed it 15 platinum

It rebuilds the machine. (also twist ending: the mimic didnt eat me, the machine summoned a clone of me.)

I feed the mimic a turkey sandwich to hold it over until it uses the machine.

EDIT: got Ninja'd