Hot Head has always been a Giant in...
...fiery temper. But it was when magic oil was discovered in Skylands that he really caught fire. As exciting as this discovery was, the party only lasted 5 minutes, at which point Hot Head felt like cooling off and jumped into the pool of oil, causing the entire island to explode!
Even though it would take another 2000 years to discover magic oil, the effect on Hot Head was immediate. It is imbued with magic oil and can produce fuel at will, which of course makes it highly explosive and capable of igniting virtually anything it touches.