This is relevant to the plot, as the rabbits are the same rabbit in different points in its timeline. It is sent on a twisting path through time and space that results in it becoming a nigh-unstoppable fighting machine. Seriously.
[SPOILERS]
John first got the original ConAir bunny from his best friend as a thank-you because he had given his friend the shades that helped redefine him. John then gave the bunny to baby Rose (Here), who repaired it in the future using the knitting supplies that John had given her previously in his time line. John got the knitted bunny from Rose later in both their time lines (But before this). He then gave the knitted bunny to baby Jade (Here). Jade, following the instructions of her grandpa (Who is John's half-clone), then modified the bunny into some kind of android weapon.
Forget all that. Here's what you need to know to understand this video: John is obsessed with bad movies. He keeps trying to re-enact Con Air because he is insane.