Getting Bitten
Apparently, it would later on be found out that Ronald had gotten a bite from one of his lizards a couple of weeks before his death. It had turned into a staph infection causing sepsis, which is what had eventually killed him. Since he kept his apartment warm for his lizards, his fever had probably caused him to head to the door for some cooler air, and ended up dying rather than getting out, and that’s when his friendly lizards ended up making a meal out of his human flesh.