the mimic refuses the cake, stating "the cake IS a lie"

i feed the mimic a flip phone

It spits out an iPhone 11

I feed the mimic my holy symbol... :(

It spits out the god on the holy symbol. The god smites you for putting it in the mimic, make a death saving throw.

I feed the mimic the god before it kills everyone. 

Death saving throw: 17

Welp... I ded...

the mimic spits out yoshiguy52.

i feed the mimic my internet connection

It spits out internet connection from a foreign country, which is 8 times faster, and 10 times cheaper (this is real, countries besides america have faster internet for way less money).

I feed the mimic America

The mimic starts to turn shades of red white and blue before spitting out a bald eagle familiar, it is now yours.

I feed the mimic a beyblade burst top. 

the mimic spits the Beyblade burst top.

I feed the mimic a cake

Taking the large number of candles as an insult to its age, the mimic eats the cake and reveals a secret treasure room as a reward for your audacity.

I feed the mimic ten pounds of roast chicken.

It spits out a live chicken familiar.

I feed the mimic a dice set.

It spits out another dice set, all with ones facing you.

I feed the mimic an alarm clock.

It gobbles it down, spitting out... a normal clock? At least the ticking inside of the mimic has stopped...

I feed the mimic an Xbox

the mimic greedily devours your klondike bar and spits forth a green glazed ceramic cup.

i feed the mimic an enchanted ukelele

It eats your ukelele and spits up Israel Kaʻanoʻi Kamakawiwoʻole (I didn't know how to spell his name so I copied and pasted it) 

I feed the Mimic a gigantic bag of Rainbow Skittles. ( because I hate them and had to find a way to get rid of them)

It vomits up a waterfall of skittles on top of you.

I feed the mimic a double rainbow

It spit up 2d100×2 gold and a leprechaun you'll have to fight for the gold. 

I feed it the leprechaun so your gold is now free.

The mimic then disappears.

I search for the mimic

As you search for the mimic, you feel very different from what you felt like 10 minutes ago. You walk past a mirror and notice something different in the mirror, you realize, you are the mimic.

I feed the mimic Ed Greenwood.

I spit up the forgotten realms of abeir-toril.

I feed myself a pill that makes me not the mimic anymore. 

The pill works, you notice the closest object is now the mimic.

I feed the mimic a sword.