Assets in a showcase scenes demonstrate the three types(Scripts) of behavior leeches:
1. Neutral, movement across random points on Navmesh.
2. Escape in the sight of a "Player", leech is looking for a new point and accelerates their movement.
3. Combat patrol, the leech moves at random points on NavMesh. When the "Player" enters the field of view of the leech, it accelerates, moves to the player and attacks him. If the player disappears from sight, the leech moves to the last position.
In all 3 behaviors available speed change in different states.
Bonus: the script that allows you to change the material Leeches switching on stage.