Anon didn't pay taxes back in the human world and now that his former government has found him, and they will take him back to earth by any means. [fun fact the only thing the joker fear's is the IRS]

source of picture https://www.dontmesswithtaxes.com/2022/11/irs-ci-domestic-and-global-tax-crime-efforts-pay-off-in-fy2022.html