How do i make a hulk transformation?

So Aztralzz is correct, this isn't a request site, so due to how complex this could be for a beginner, I can only explain how it works and not give you a script (because how will you learn if you don't try it yourself first).

So, first we'll start with the Input. There are currently two ways of handling input: UserInputService, and ContextActionService. I recommend using the UserInputService simply because its easier to work with in my opinion, but it's up to you. For example, in UserInputService, you can specify if you want it to occur when the key is pressed (InputBegan) or released (InputEnded).

Next would be to handle the transformation sequence. For this, I recommend you use the TweenService. It allows you to specify the parts in the player's character to transform and also allows you to determine how long the transformation would take. Now the main reason why I recommend this is because it is easy to use, but also because you can set the time it takes to transform to the length of the sound effect you want to play.

So all of this put together:

You would make a function containing everything for the tween service, and you would have a function handling input that would check if the key was pressed and then call the tween service function. Then you would have this input function called when the UserInputService.InputBegan event was fired.

Link for everything you need to know about the TweenService: https://developer.roblox.com/en-us/api-reference/class/TweenService

Link for everything you need to know about the UserInputService: https://developer.roblox.com/en-us/api-reference/class/UserInputService

If you need clarification on anything, feel free to leave me a comment below, and also don't forget to mark this as the accepted answer if it clarifies everything for you.

First off i wasnt making a request. 2nd off i was only asking how to do it myself.