It took awhile, but I was finally able to obtain Red’s Stone Guard class by collecting enough of the various items in the Into the Jungle event. From what I understand you will also be able to purchase this headgear in the store. The Stone Guard class was included in the Into the Jungle event, which you can read more about here.
If you have a different strategy for completing this level feel free to leave a comment below. Be sure to check out the rest of our Angry Birds Epic walkthroughs here as well as join the conversation in the Epic Forum.