After Amy got the dog in early 2000 (then named "Tank"), her landlord forced her to give him back to the prior owners before it was decided in July 2000 that she could keep him. The act of her getting a prized treasure and then having to give it back reminded her of April 2000 when Chris Jericho won the WWF title from HHH, only to surrender the title back to Hunter when the referee overturned his victory. Therefore, the dog was named "Jericho" based on the similarity of those events.
Jericho's middle name "William" was taken from Bad Ass Billy Gunn.
If Jericho were Catholic, then the name "Michael" would be his patron saint name. However, he is not Catholic and "Michael" was taken from Shawn Michaels.
And of course, his surname "Ray" was taken from Amy's family name.
His nickname of "Jeribear" was the first name Kay called him upon their meeting in August 2006. Amy thought it was fitting as she had been calling him "Pooky Bear" for a number of years. Surprisingly, the nickname was not inspired by Mr. Mackey claiming he could not attend a Grateful Dead concert because "Jeribear is dead, man." Conversely, the nickname of "Dog" was a direct influence of Stewie's name for Brian.
Sadly, Jericho suffered through a bad case of parvo as a puppy, but luckily, he has survived his reduced lifespan which often befalls afflicted puppies. Jericho moved to Arizona with Amy and Kaena in September 2007 after living in Galesburg, Illinois for over seven years. They stayed in Mesa until March 2011 when they moved back home to Galesburg.