How to make a custom action???

[flyingxmango]

Alright, I've been working on a character that's similar to a mandrake, and his key ability is being able to plant himself like the mandrakes in game do. How would I code that? I'm assuming I could use the Mandrakes animation as a reference for creating the custom animation, but where would I even start with coding this? 

Being planted needs to grant him some of the effects of wearing the bush hat in terms of hiding from monsters, so I need to be able to add code to the action itself,

Help???????