This moment is underappreciated as a piece of Joss Whedon writing genius. Do you see what he’s doing here? He’s evening the playing field.
See, Thor might not understand the Wizard of Oz reference, or realize that Midgardian pet shops don’t sell animals large enough to ride, but there’s shit that humans don’t understand about his culture, too. He doesn’t know about flying monkeys? Well, Asgard has this thing that you’ve never heard of, either. Thor is not an imbecile in the world of the savvy; he’s on equal footing with them now.
Thor: We on Asgard act like we are more advanced, but we come here battling like Bilgesnipe. Coulson: Like what? Thor: Bilgesnipe? You know - huge, scaly, big antlers… You don’t have those? Coulson: Don’t think so. Thor: Well they are repulsive… and they trample everything in their path.
A bilgesnipe is a creature that is referred to by Thor in the first Avengers movie when he is speaking to Agent Coulson with regards to Loki’s actions on Midgard. When Coulson says he does not know what the creature is, Thor describes it as wreckless and repulsive; with ‘huge, scaly, big antlers’. We are never given a visual of the creature.