He did actually hatch from an egg.

There will probably not be any opportunity in this story to explain how Roger’s species ended up on Venus. It’s a back story I’ve actually developed quite a bit around, but I need to prioritize my world-building. It doesn’t matter to the plot or the theme, it didn’t work as a vehicle for plot or character development, so you don’t get to see it. I haven’t even told you what his species is called.