The Qtest Spawn, known as the Tarbaby, acts quite differently compared to the final version. Instead of jumping towards Ranger at high celerity, it sluggishly crawls up to him and will assault him only if he exists right next to it. This attack is very brief, lasting a single frame, meaning it is a jarring transition.
Its collisions cause no damage and it does not explode when killed, thus rendering it completely innocuous.[1]