Blueberry

The Blueberry is a parasitic creature that captures and then feeds on its victims, at first the blueberry looks like a normal earth blueberry [although the fruit can be found on millions of planets now] after the berry is ingested it quickly swells in the stomach and then forces a blue ooze like goo to erupt from the mouth and nose that quickly forms to cover the body and then bloats outward into a ball like shape but leaves its victims features and body shape at the top of the now six foot ball [for a standard human] as the blueberry digests its prey it shrinks in size back to that of a normal sized blueberry.