Mob Variants

To create an entity you need to click on the "add new mod element" button and then select "living entity". After that you will be able to select a custom texture, and make a player-like entity with custom textures. If you want to make a custom entity like a dragon or something new, it's a bit more difficult. You need to install blockbench (which can be found here: https://www.blockbench.net), and create a model, with textures there. Then export it into a .java file and import it into mcreator.

Please respond if you have any other questions :)