Tomacco
A tomacco is a fictional fruit that is half tomato and half tobacco, from the 1999 episode "E-I-E-I-(ANNOYED GRUNT)" of The Simpsons.
Homer Simpson accidentally grows tomacco by fertilizing his fields with plutonium. He sells the bitter-tasting fruit at a roadside stand, and sales boom thanks to tomacco's extreme addictiveness. Laramie cigarettes offers to buy the rights to market tomacco for $150 million, but Homer refuses, demanding $150 billion instead. This offer is rejected by the company's executives. Eventually, all but one of the tomacco plants are eaten by farm animals. The company executives manage to steal the last tomacco plant as they depart, but a tomacco-crazed sheep attacks them, causing their helicopter to crash and destroying the last remaining plant.
In 2003, inspired by The Simpsons, Rob Bauer of Lake Oswego, Oregon successfully grafted a tomato plant onto the roots of a tobacco plant, which was possible because both plants come from the same family, Solanaceae. The plant did produce fruit that looks like a normal tomato, but Bauer suspects that it contains a lethal amount of nicotine and thus would be inedible.