Thanks for posting this! Was able to track each pet and add the plushies too, just like you did <3
EDIT:
ZΕL wrote:It's technically right, in a very interesting way!
The first chicken is from a christmas litter that is all-together based off newborn stages of older pets. For the most part, that means blanket designs, but in the case of this chicken, it's literally based off a nest!

The nest of the March 2013 chicken litter, which also produced this outcome:

So I guess you could argue that this bouncy chicken represents two pets at once.
The hen may be a slightly better fit because the plush lacks the red skin in the face present on the rooster, but it's a pretty funny situation, haha.
Just gonna add to this as well as I didn't see the chickens of the other plushies posted:

November 2011

September 2013 (not 100% about this pet!)

December 2013 (not sure either)

September 2014
Please correct me if I'm wrong!
And for the wonky plushies, has anyone posted all the pets they're based on?