This is real: one hundred trillion dollars bill

It happens only in Zimbabwe. Below find some facts as how this happened.

The Zimbabwean dollar was the official currency of Zimbabwe from 1980 to 12 April 2009.

Although the dollar was considered to be among the highest valued currency units when it was introduced in 1980 to replace the Rhodesian dollar at par, political turmoil and hyperinflation rapidly eroded the value of the Zimbabwe dollar to become one of the least valued currency units in the world, undergoing three redenominations, with high face value paper denominations including a $100 trillion banknote (1014). The third redenomination produced the “fourth dollar” (ZWL) which was worth 1 trillion ZWR (third dollar) and 10 septillion “first dollar” ZWD, so overall the ratio of the redenominations was 103 × 1010 × 1012 = 1025. (via Wikipedia)