They just seem to have a few things in common.
Putting this in scraps because it took literally like 15 minutes of derping around in Photoshop instead of, you know, actual effort. I simply wanted to share what I hope is a mildly amusing thought.
Pinkie Pie from My Little Pony: Friendship is Magic belongs to Hasbro.
GLaDOS from Portal/Portal 2 belongs to Valve.