You’ve likely seen a variation on this, sometimes called the Frankenstein squat, before. Both basically use a “front crouch without hands” position. Here’s Christian Thibaudeau doing the heavy, bottom-up version:
The halted zombie squat, which starts from the top, is one of the best exercises for teaching an efficient pattern of movement when squatting from the front. It’s a fantastic “self-limiting”
Zombie Squat stopped
Everything has to fire in a coordinated and efficient manner, or the rod will roll off your shoulders. The break down below forces you to hold on tight, makes sure your movement is blocked, and instills confidence.
This variant can also be used as an aid to learning a good pole position and an upright trunk during the front squat. The rounding of the upper back is a very common mistake with the front squat (and the cup squat), but it is eliminated with the paused zombie squat.
Related: A powerful new way to squat
Related: Front Squat Bar Placement