I think it's pretty extreme, anyway: Seal Knife-fighting!

In the water, of course, only fair.

Caring for a 3 year old when you are bedridden sick.

I'm not sure what to call it but OH BOY is it tough.

...a sliding-down-the-hill-in-a-bathtub-ahead-of-molten-lava contest?

That's pretty extreme, no?

How about Backwards Downhill Mountain Bike Riding

Unicycle Mountain biking.

Dodgebomb!

...razor blade gargling?

Running from one airport terminal to another to make a 10 minute connection window, hauling laptop and an equipment case, dodging seniors and other tourists, while dressed in heels and a suit.

Compared to that, surfing over molten lava is child's play

I made the connection, btw!

Horse and shoe:
Like horseshoe except you don't just throw the horse's shoe.

High-tension electric fence vaulting?

(prototype rules and equipment developed at a local prison)

Glass eating?

Sterno-gel snorfling ...

(that one'll wake up yer sinuses...)

ka boom... try to invent the most interesting way to make a car go to peices as quickly as possible...

competition cross-country luge (like moto-cross on blades...)

two vehicles with BIG spears welded on the front make a run at each other on a sheet of ice. Kinda puts the skids on "chickening out"...