Zebra in plane?

Okay, I'm okay with the fact that they rebuilt the plane, flew the plane, destroyed the plane, and rebuilt the plane. However, my question is, after Alex gets banished from the pride, and Gloria is talking about her upcoming date, and Melvin thinks he's going to die...why is that other zebra there, joining in the conversation? Who is he? He's not posing as Marty, he's apparently just hanging out. Why?