Okay, I could've sworn there was this one movie about this butterfly mother with two adorable caterpillar children, a boy and a girl, who fend of an invasion by shapeshifting aliens with glowing eyes who want to capture and eat Earth creatures. I remembered it was called "Katie and the Caterpillar Kids" but a Google search for this title yields absolutely nothing. Even IMDB hasn't got squatt on it.
Did I just imagine this film? I can't have, because, dang it, I remember so much of it so clearly beyond just the basic plot outline; I remember there's a punk hawk, a mouse police inspector, and that the little boy caterpillar defeats the main evil alien using his harmonica somehow. Is it just under a different title? I've remembered movies by wrong titles before but any search for "Katie" and "caterpillar" has yielded nothing so far....
Any relation to Katy aka Katy the Caterpillar?
http://www.imdb.com/title/tt0087543/
Ah-ha! I used that spelling of "Katy" and discovered the title is actually Katy and the Katerpillar Kids, not Katie and the Caterpillar Kids. It's also known as "Katy Meets the Aliens."