Have you ever visited a Server where the Lobbies are made out of some impossible to get parts of a block or a frozen block state?
Have you ever wanted to use a block for a build but it's just too expensive to mass produce?
Or maybe you are simply tired of your friends teleporting the Dragon Egg away from where you put it.

Then Copycat is the mod for you!

Copycat introduces a simple solution by adding a paste regurgitated by felines which is capable of cloning block appearance without any functionality of the original block. It also removes any restrictions, like must be attached to a block, be on a certain block, must be underwater, etc. the block came with, while also adding waterloggability because why not?
And even better; This does work with any of your favourite mods!
(Only exception at the moment is Tile Entity Renderers won't display which might change in the future so there is a high chance you might encounter some invisible parts/entire models in the copy. All Vanilla cases of fully invisible models are blacklisted)

vvv For more info visit the spoilers below vvv

Get Started

To get started you need Slime Balls and own a Cat (The Cat must be tamed by you), then feed it a slime ball by Right Clicking it. After a short moment it will horf up some Copycat Paste with which you can craft the Standard Copycat Paste with which you can start cloning blocks.

To clone a block, simply SHIFT + Right Click on a block you want to copy. If it is allowed (check Copy Rules section below) the state of the block will be saved and you can start placing the cloned block down. Each use consumes a unit of goo in the tube (doesn't break when it reaches 0). To refill it, simply use the paste type that was used to make it (for the above that would be Copycat Paste, each restoring 4 durability) in a crafting grid alongside the tube you want to refill.

If 16 units of goo is too little for you, you might want to upgrade it to the Ocelot-Grade Copycat Paste which is made with Copy-Ocelot Paste. To obtain it you need some Copycat Paste and an Ocelot that trusts you, once again feed it the Copycat Paste by Right Clicking it and you will receive some Copy-Ocelot Paste with which you can craft the upgrade. This type can only be refilled by using Copy-Ocelot Paste (12.8 durability each).

However 128 units of goo might still be too little for you(, or perhaps you are just tired of refilling it), this is where the Lion-Grade Copycat Paste comes in. Imbue your Ocelot-Grade Copycat Paste with the power of a Nether Star and the goo will never run out!

Copy Rules

As this would be similar to Creative Mode, Copycats have a few rules they follow (by default)

A Copycat is capable of copying:

Blocks with Block States
Blocks (/- from Block Tags) that are featured on the Whitelist (config)
A Copycat is not capable of copying:
Blocks without Block States
Blocks (/- from Block Tags) that are featured on the Blacklist (config)

The config file's default lists for both types explain why their entries are there so give that a look if you are curious.

However these are the default rule sets which doesn't mean you can't change them...

In the config file you will find a few settings that you can set them to:

Copy all without a care in the world \o/
Copy everything but things on the Blacklist
Copy nothing but things on the Whitelist

Lost Copycats

In a world where any block can be an impostor it might be hard to keep track of what is what, this is where the Copycat-Vision Goggles come in!
When equipped all Copycats will show themselves (In whatever the particle render distance is) as it is only obvious that copycats can see other copycats, duh!

Copycat Goo is also relatively soft and breaks relatively quickly, however one can speed it up further by using a Shovel

(In case you are curious you can put this mod like all my other (future) mods into your lovely modpacks!)

Important
This mod doesn't work with Optifine, nor will it. Optifine is a closed source mod and changes about everything when it comes to rendering. As this mod would never work without manipulating a bit of rendering itself, it wont be able to work in the changed enviroment caused by Optifine. Ever. If you ever make a mod yourself that changes everything about the game you mod dont make it closed source.