It looks like a mini-nuclear bomb, to be honest. But it’s just the result of pouring water onto an oil fire (don’t ever do that!). In this video by Crash Zone, you can see the liquid fire drip down into the ground and then charge right back up creating a truly epic and fiery mushroom cloud.
This could be turned into a really effective PSA with Thanksgiving just two days away. So many people frying turkeys with loads of oil. Your sister site had some tips a few years back. Kitchn has a good article too.
You can and should buy the Class B fire extinguishers mentioned on The Kitchn at just about any large retailer; like Target, Wal-Mart, or Home Depot.