Awesome

unity-sprite-cutter

Simple solution for cutting sprites in your game.

What it does, exactly, with given GameObject:

• converts SpriteRenderer to identical MeshFilter/MeshRenderer components
• cuts through the mesh - the Texture itself isn't cut, all magic comes from setting "cutted" UVs
• converts BoxCollider2D and CircleCollider2D into PolygonCollider2D
• cuts through the collider paths
• returns cutting result as two new GameObjects (so you can still do whatever you want with the original one) or as one ("cutting off" new GO from existing one)

Limitations

• EdgeCollider2D isn't supported.
• Non-convex Collider2D shapes aren't supported.