Problem/Bug Making cows rideable

Hey, I have dilemma in regards to cows. For shits and giggles, I am trying to make cows rideable. But this is my second plugin ever. Granted, I know Java pretty well. So I've thought of several ways to approach the situation, but none of them are working. Should I try to edit the Cow interface and get it to implement AbstractHorse? How would I go about doing that? Or should I create a class that implements the Cow and AbstractHorse interfaces and then whenever a Cow spawns, I cast it as this new ObjectType? I tried this, but it wants me to define every single abstract method declared in every single interface leading up to Cow. I'm not going to do that. Only to find out that it might possibly work. Does anyone know what I should do? And how I would do it?

 

@kyle71698
The "easiest" way of doing this would be to create a custom entity that overrides cows. You can use this util and just update it for your current version. If you do not know how to update the util, you can try to ask for someone else to do it for you.

[Edit] Why is this in Bukkit Alternatives? What type of server are you using (cauldron, bungee, spigot or paperspigot)?