Ryuk Uchiha's personal cursemark that he created in order to quickly kill, bind, spy on, and even control his targets. The Spider's Seal is a multipurpose cursemark, that requires Ryuk to bite the target in order to induce it. Once the target has been bitten a pitch black seal that has the appearance of a spider will appear on the location that had been bitten. The cursemark is made from Ryuk's Yin chakra and allows him to change the properties of what the seal can do in order to meet his needs, however the seal can only use one ability at a time and requires a lot of chakra to be used.