How Many Different Entities Could Transform By The Moment The Story Reached The Frieza Saga?

[Sovran Nila]

It was mentioned that only a handful of individuals in the entire universe could transform, during the Frieza Saga. How many were there in total?

Gohan - Oozaru
Vegeta - Oozaru
Zarbon - Monster
Freiza - Second form

Were there any others?
Does Kaio-Ken count as a transformation?

 

[Papasmurf]

there's man-wolf who switches forms from a wolf to a human.

 

[Papasmurf]

If you count non-canon entities there's also Garlic Jr. and his men