The texture files are seperately downloaded in your gumroad files.
It's a .Zip file that contains the .psd, .clip and substance painter files for the Body, Extra and Prop textures.
The slugcat has 4 Textures. The first is the main body, the second is the "extra" texture for all the added features, and the third is the props, and the last is a pearl MatCap texture. The matcap texture adds an effect on the PC material where it makes the pearl look reflective! You need to colour both the pearl on the props texture and the matcap. (The quest material just uses the texture.)
Texture 1 - Body
Texture 2 - Extras
Texture 3 - Props
Texture 4 - Pearl Matcap
I recommend either photoshop, clip studio paint, paint.net, GIMP or any other art/editing program that supports .psd files!
For my examples I am using Clip Studio Paint.
On the right are the layers which is what you need to change the colour of your slugcat. They all have masks, meaning that if you fill those layers (usually the command is ctrl+f), they won’t just fill the whole layer, only the parts that the mask covers.
Go through each layer and pick a colour for each part that you want! Note as well, the shadows are not obligatory and you can leave them out if you would like a much more flat-coloured look to your slugcat.
The "Extra" texture file and "Props" texture follow the same formula.
IMPORTANT: Make sure to hide or delete the “UV” layer as it is just there to show the way the UV is layed out over the texture.
As well, make sure to hide any layers that you don't plan on using by clicking the Eye icon (Or the equivalent on whatever program you're using). If you don't do this, stuff like the scars and spearmaster tail will show up.
Lets use the slugcat from the previous section as an example for texturing!
I'm making the slugcat lime-green with deep purple eyes and bright purple pupils. I'm also adding the scar on the eye, but I'm going to make the splotch dark green and the scar black, like the eyelashes.
I'm also going to make the rivulet gills fade to bright purple. (Note: "Gills Secondary" is the transition colour, so it should be the same as the slugcat body)
Lastly I will edit the props: I'm going to make the vulture mask light pink, and make the pearl bright yellow. This includes the matcap texture.
With the way the project is set up, applying your new textures is simple!
The custom slugcats are all set up with their own textures in this directory:
"Assets > Slugcat DX by Teevz > Materials+Textures > Custom Textures"
Once you have your new textures, all you got to do is replace the corresponding textures in this folder, and it will automatically apply.
There are a couple of methods to do this.
Example of Method 2.
Method 1. Save over the .png files from whatever art/editing program you're using.
Method 2. Right click in your project and click "Open in Explorer", and delete the .png files. Copy your texture files from wherever you saved them and then paste them into the folder, and rename them to the same names of the files you deleted.
Once you've done either of these methods, click back into unity and it should update them automatically!!
That should cover all of the basics on how to customize your own slugcat!!