Design your own pandemic

Create your own world-spanning illness! Customize the symptoms! Experience an outbreak! You can make this serious (seizures, paralysis, organ failure) or ridiculous (uncontrollable singing, unsightly tentacle growth, levitation) or anything in between. It's up to you. This scenario is kind of heavy on the prompts (you're designing a pandemic, after all) but I've tried to make them flow nicely. Try to write your symptoms as the end of a complete sentence, so write "coughing, sneezing and/or fatigue" rather than "coughing, sneezing, fatigue" for example.