Common Issues

Animal is not Moving

You are making a custom animal, but when you try to move it, it does the animations, but won't move forward. Most of the time, the animations you are using are not RootMotion.
Check this Tutorial.

Animal is falling near the ground

If the animal start to fall for no reason, it should be because Ground Layer in the animal controller is set to Nothing, or the layer of the Game Objects considered ground is set to a different layer.
The Default value for the Ground Layer is Default. You need to add your other ground Layers to the Animal Ground Layer Mask.​
Ground Layer is set to Nothing