At least in England, parody is not a defence to a passing off or a defamation claim. You may in theory also be exposed for trademark infringement, etc.
However, as I am forever repeating on these forums, the real issue here is a practical one. Do you think that large companies like these are going to waste time and very valuable legal costs doing nasty things to you?
As I know from my own practice, large companies only take action against individuals when they are left with no realistic alternative and a "cease and desist" letter has been ignored.
Cheer if you like bears! Cheer if you like jam sandwiches!
Quote of the week: "... I started learning DBP while I was a Satellite Network Controller for the US Army Space Command ... "