GooGoo Marshall is a pre-made male foal featured in Appaloosa Plains. He was adopted by Felipe and Kim Marshall in order to comfort Kim's deepest wish of having kids which she hasn't fulfilled. However, GooGoo still misses having a 'real' mother. It is wondered if GooGoo, when grown up, will have as much attention as he has accustomed to, since Kim still wants to be a mother.
GooGoo also lives with Oopsie-Daisy and BaBa, a kitten and a puppy respectively who are his enemies. GooGoo is best friends forever with Kim, and friends with Felipe and Hailey Shepherd. He has not learned any skills or behaviors from his owners.