Astronauts infected with Space Parasites!

I've been doing some sketches of a series I am working on. The story thus far is that these astronauts were on a mission that took them into deep space. During their journey they somehow got infected with space parasites that, once back on earth, started showing themselves and taking over the astronauts bodies. These sketches are brainstorming, I haven't quite gotten the look down yet, it's not exactly what I have imagined in my head, but close. Check it. Give me your feedback!

This first guy has been transformed into some kind of flying bat creature. He flies around cities all over the world still wearing what remains of his space suit.

This next fellow has had the misfortune of being infected with a gigantic moth type insect who is much larger than the ones found on Earth. The creature is trying to take flight but cannot get airborne because it's dragging along the still live astronaut.

This nasty fellow is growing inside the confines of the cosmonaut's still intact space suit. The creature is finding gaps in the seams to continue growing from.

Lastly there is the crab monster, the largest of all the parasites. The human host is just along for the ride.

These are all ideas I have been playing with. I am still trying to find the groove.