Place your eggs in a single layer in a pot and cover them with at least an inch of cold water. Bring the water to a boil over high heat, uncovered, then let the eggs cook for 10 minutes. Once they're done, drain and run them under cold water right away to stop the cooking.
Once the eggs are cool enough to handle, gently crack the shells all over using the back of a spoon, or simply roll each egg firmly on the counter. You want lots of small cracks across the whole surface, not big chunks removed, since those cracks are what let the dye seep in and form the web design.
Fill a large bowl with cold water and whisk in black food dye until the water turns fully black. Submerge the cracked eggs completely in the dye bath, then cover and refrigerate for at least 4 hours, or overnight for the boldest pattern. This step is what turns plain hard-boiled eggs into true halloween deviled eggs eyeballs and web-cracked showstoppers.
Once the eggs have soaked long enough, carefully peel away the shells under cool running water. You should see a beautiful marbled, spider-web-like design across each white. Slice every egg in half lengthwise and gently pop the yolks out into a separate bowl.
Add the mayonnaise, dijon mustard, green food dye, hot sauce, smoked paprika, salt, and pepper to the bowl of yolks. Mash everything together with a fork until it's completely smooth and creamy, with no lumps left behind. Taste and adjust the seasoning if you'd like it tangier or spicier.
Spoon or pipe the green filling back into each egg white, mounding it slightly for a fuller look. A piping bag fitted with a wide star tip gives the cleanest, most professional finish. Finish each egg with a sprinkle of black lava sea salt right before serving for that final spooky touch.