I've never made a mod except adding in a few custom weapons to Terraria but I do know the basics and have taken a class on C#, so if you need some coding help I could help out. (Though I don't have too much extra time with school and stuff)
Awesome idea, I love Wyverns as well! I'm a pretty bad spriter but I could probably mod in a basic Wyvern summon or pet. (I've never made a mod before, but I'm taking a programming class so I know the basics)
I joined like a week ago, but hello everyone! I've been playing Terraria since... well, since it came out on mobile, and started playing on PC about a year ago, and I finally decided to join the forums.