Hi! I am not able to find a plugin that is for Minecraft 1.15 that is based on mob-morphing. Sorry for the brief request, I will edit this if necessary.
By mob morphing you mean disguises? In that case here is a good one: https://www.spigotmc.org/resources/libs-disguises.32453/ It does not look free at first, but if you scroll down there is a free version link.
So, I found out that it did its job, it was open source, but it was paid software. I found the source at GitHub: https://github.com/libraryaddict/LibsDisguises/tree/master/src/main/java/me Any way to convert the master branch into a jar/json plugin?
Hey. If you read it more carefully, under "why is it premium?" is also a free download to a jar file.
