Pyrogeddon is a Spark that appears in Mario + Rabbids Sparks of Hope. It is located in the Darkmess Puddle battle A Cold Greeting. After the battle, Pyrogeddon joins the heroes on their adventure.

Pyrogeddon is a red Spark with pyrokinetic powers that rides an orange fiery cloud, possibly in reference to Sun Wukong (also known as the Monkey King), a character from the 16th-century Chinese novel Journey to the West who was known for riding on a cloud. Its appearance, cloud, and ability are similar to Electrogeddon, Cryogeddon and Vampgeddon.

Source: https://www.mariowiki.com/Pyrogeddon