Kings of Pain

Adam and Caveman Rob take on America's biggest and most deadly scorpions. But their surprising result is a hugely painful wake-up call - and a new Scorpion King is crowned.[HISTORY Channel]

Adam has a phobia of tarantulas, so naturally Caveman Rob picks two of the world's nastiest ones for them to endure, including a tarantula with the well-deserved nickname: Orange Bitey Thing.[HISTORY Channel]

Adam and Caveman Rob get bitten by one lizard whose venom is in doubt - but not its ability to latch on and tear flesh - and another whose venom is notoriously painful.[HISTORY Channel]

In a tribute to the godfather of the pain index, Dr. Justin Schmidt, Adam and Rob tangle with a new batch of extremely painful and deadly insects; one colony of ants kicks the Schmidt out of them.[HISTORY Channel]

Thinking he's getting his revenge on Rob for selecting tarantulas earlier this season, Adam programs Rob's phobia: centipedes. The joke is on Adam, though, when one produces one of his most painful bites ever.[HISTORY Channel]

Some of the most painful animals around can be found in the backyard; Rob and Adam take on an Assassin Bug, a Jerusalem Cricket, and the Brown Widow Spider--producing a record-setting episode of pain.[HISTORY Channel]

Rob and Adam test the pain dished out by a trio of unlikely creatures commonly kept in home aquariums; they proceed to ruin the image of a popular cartoon movie character for millions of children.[HISTORY Channel]

Rob and Adam test the yellow head moray eel for possible venom effects, but must resort to a risky, bloody bite; venom is not the issue for the electric eel.[HISTORY Channel]

It's America vs. Australia in a battle royale of pain administered by sharks. But after getting stung by both, Adam and Rob realize that when their countries win, they lose.[HISTORY Channel]

Adam and Rob serve up their most annoying stings in the history of the Pain Index, and chase them with a tiny fish that has venom to die for. [HISTORY Channel]