- A bouncy rock
- A bull
- Tail flips
- A leaping walrus
- Some angry eyes, and an angrier tail
- A butt mouth
- A pine cone
- A tyrannosaurus cat
What do these things have in common?
The Crimson Chin, a sick chicken, and a dog with fleas do not have this same thing in common with each other or the other things.
Number 3 has a male counterpart, whose Rage-Inducing Tupperware is perhaps the most famous.
The pine cone is often referred to as "Steve".
The through-line is not the franchise.
In response to feedback I have received:
Number 1 does not itself bounce, but causes everything that touches it to bounce.
Number 4 is not thick and blubbery like a walrus, instead being thin and agile like a cat.
Number 5 lives in the jungle, and is known for its speed.
EDIT 1: Updated hint 5