Interaction with the creature model and the variety of their textures.

I'm completely new to this and don't know en well, so I hope the translator doesn't distort the meaning.

Let's say I have a Living Flower Pot entity in which the player can plant a flower like in a regular Flower Pot. How do I make the entity model change after interaction?  Do I need to make a separate Living Flower Pot model for each type of flower, or somehow modify one by adding a model of a flower on top?

Can I interact with model elements at all in the MCreator editor? For example, to make the zombie's head increase from hitting the Windcharger? Make his one arm disappear due to low health(like PvZ)?

Going back to the Living Flower Pots, how can I make variations of their textures(or even of their models), similar to how it is done in the Animania with animals.