Cassette Beasts has built-in support for user-created mods. See:
Monster Making Guide
This is a 3-part tutorial series written with the goal of taking the reader through the whole process of creating their own monster for Cassette Beasts, from a conceptual stage to implementation. An example mod will provided once this is complete.
- Monster Making Guide Part 1: Concept, Art & Animation
- Monster Making Guide Part 2: Fusion Forms
- Monster Making Guide Part 3: Implementation & Integration
Whilst this doesn't exist yet, .ase templates for human character's head cosmetics can be found below: