The starfish is more like a Face Hugger from the Alien franchise. Although it this case it's more like a Crotch Hugger instead, and unless it has an official name, that's what I'm gonna call it. It's also on the screen past the Strawflies.
Personally, this one really shot up into my favorites. It's kinda bare bones right now, as it's incapable of being killed and incapable of killing Nona, but I really like the animation. Basically, it jumps up and grabs her crotch and gets her Erotic up. Then, once she's futa, the dildo thingy pounds her ass. It's a lot like the green spider things from the spider fight in Fairy Fighting.
I think it'd be great if, in a future update, we could possibly throw a second one in the mix for her face, and a couple of the Breast Flowers for a full-on orgy.