Sounds like a great idea
@rhombus . I imagine Littlefoot or someone seeing something land far off of the side of the valley before going to check it out, probably after getting the gang together. Then it can used to introduce whatever plot device that is related to the Rainbow Faces (Maybe my robot dino OC. XD)
My OC will be named Al, it's like A.I. but with a L instead of an I. He is a quirky fellow who wishes to learn about the world around him, as he is a newly designed robot to research worlds while being hidden. However the land procedure went array, resulting in a system error that causes a condition similar to amnesia. Don't worry he isn't gonna be a robot Guido.
He is adventurous and likes to say hello to everyone he see's, sharptooth or not. I'd imagine the sharpteeth would show disinterest in him because he is a machine, and would use this as a advantage. I think his personality could be a result of the male Rainbow Face wanting him to be a companion and swooped it in while the female Rainbow Face wasn't looking.