Orochimaru chugged down the cough medicine, completely ignoring the warning label that indicated that one of the medicinal herbs in the concoction had mild hallucinogenic properties when consumed in large enough doses...
6 Months later:
The new recruit, a young Genin named Kabuto raced into Orochimaru's quarters looking badly singed and rather worse for wear.
"Sir!" Kabuto yelled. "The fire breathing monster chicken has escaped!"
"The...what?" Orochimaru said, feeling his brain break as he tried to process the child's statement.
3 Days later:
A seven year old boy named Uzumaki Naruto settled down for the night underneath a tree after spending the day aimlessly wandering through the miles and miles of woods surrounding Konoha. The temperature reached near freezing levels that night, but that was okay since a giant chicken had sat on him and kept him warm.
The next morning, Naruto led the chicken which he'd named Bawk into town, grinning from ear to ear since he had a pet he could bring to Show-and-Tell. He'd gone into the woods looking for one, and had thought that he would have to go home empty handed.
Later that morning, when the Kyuubi Jinchuriki rode into a classroom that was starting to look like a menagerie due to a rather poor idea that had been borrowed from the civilian elementary school on a five foot tall chicken, the only thing that was going through the Instructor's mind was What. The. Fuck...?
The next morning:
The Hokage sighed as he wrote up a D rank mission to create a giant chicken coop for Naruto's new pet which he was sure to receive a number of complaints about. He made a note to insure that it was fireproof as a six foot gout of flame nearly incinerated Homura.