How to use Wolf entity model (or other non-built-in models) when creating new Living Entity

I'm using MCreator to help my kid build a mod. We're trying to create a Wolf-like Living Entity, but "Wolf" isn't one of the built-in entities in the entity model drop-down.

I took a look at the MCreator source code, and it seems that it contains a Wolf entity model, but that entity isn't listed in the combo box list (https://github.com/MCreator/MCreator/blob/master/src/main/java/net/mcre…).

Is there a way to use a Wolf entity as the entity model in a new Living Entity? Is there a way to add a new model to the list of built-ins? Thanks!