The first instance of the rubber snake being used was in the "Snake in Bed" video where he finds a dead snake in the backyard and puts it in Grandpa's bed which alerts his survival instincts and frightens him. This was an early video of the show when in ran from 2007-2010 before being banned on youtube but later on being resurrected again. This video is only found on archive channels now.
The second video shows Michael doing more of the same thing as the first video but this time, he convinces Angry Grandpa that he was bit by it with fake blood pouring down his arm. Chaos ensues as Angry Grandpa thinks the venom is going to kill him before realizing the error of his ways.