Just to show again that I did not invent a monster but used a prototype. Of course it is not a classic space invader, but it exists and could be found in different stock images by key words "pixel monsters":


Changes: one more column to the center, one more pixel for every leg, eyes aligned with the mouth

Prototype monster available in these popular stock databases:
Stock #18930301 in vectorstock
Stock #105309653 in dreamstime
Stock #764317714 in shutterstock