I was in the produce department the other day and came across these: "Goblin Fingers" - Yikes! It turns out that this cleverly marketed and rare fruit is really called "Buddha's Hand Citron".
This wild looking fruit is actually a a very old form of citrus. It's been called "lemon with fingers" but has no flesh or juice inside. It's all rind and pith. Mostly it's used for zest or for infusing into liquors or other spirits like lemon cello, and obviously fun for Halloween decor. You can also make salts or sugars with it and use it in pickles, preserves or salads and anything else you can think of. Its rind is not as bitter as that of a lemon and great for anything needing lemon zest.