Unity's Sprite Editor knows about sprite sheets, and once the correct Grid size has been entered, it treats the items in each Grid square inside the sprite sheet image as an individual image, or frame, of the animation. In this recipe, you selected sub-sequences of sprite animation frames and added them to several animation clips. You added an Animation Controller to your GameObject so that each Animation Clip appears as a state in Animation Controller State Machine.
You can now repeat this process, creating an Animation Clip called monster-attack that uses frames 8-12, and a third clip called monster-death that uses frames 15-21. You can then create triggers and transitions to make the monster GameObject transition into the appropriate states as the game is played.
You can learn more about the Unity Sprite Editor by looking at the Unity video tutorials at https://unity3d.com/learn/tutorials/modules/beginner/2d/sprite-editor.
You can learn...