Driftveil City Pokémon Gym Leader: Clay "The Underground Boss"
Pokémon Black and White
When the player first arrives in Driftveil City, Clay will be mad at them because when the Driftveil Drawbridge was lowered in order to let them into the city, a group of Team Plasma members Clay and his underlings had caught escaped. Thus, Clay only lets the player challenge the Gym once they've found and beaten Team Plasma at the Cold Storage.
The Driftveil Gym features a number of elevators that are in the mine shaft layout which must be navigated up and down and girders which need to be crossed to reach the central elevator, which will take the player down to Clay at the bottom of the mine shaft. There are five Trainers on the way down, though the player only has to battle three to reach the Gym Leader.
One of the Trainers in the Gym mentions that the depth of the Driftveil Gym helps to remind Clay that he once started at the bottom with nothing.
Pokémon Black 2 and White 2
The Gym no longer features the elevator puzzle, but is instead replaced by a conveyor belt puzzle that takes the player to landing platforms. Each time the player lands on a new platform, it lights up. Occasionally there will be viewing platforms, which allows the player to see several platforms from above. Whilst most of the conveyor belts take the player directly to the next platform in any one direction, there are some that jump a platform by traversing underneath it, leading to the one beyond it instead. This time, there are seven trainers available to battle in the Gym. However, only two of them need to be battled in order to reach Clay. As the player lights up more of the platforms, the ground becomes more visible, stalagmites of crystal can be seen jutting out of the ground, as well as air vents that connect all the way through the Gym, one of which can be seen next to Clay's golden platform. Various drilling machines, wheelbarrows and shovels also litter the floor throughout the Driftveil Gym.
Clay's Palpitoad first appeared in Battling the King of the Mines!, where he was used in a Gym battle against Ash. He easily defeated Ash's Oshawott, after which he battled with Snivy. Snivy started by using Attract on Palpitoad, which became infatuated, thus making him unable to attack and an easy target for Snivy, which hit him with all of her attacks and finally defeated him with a Leaf Storm.
Clay's Excadrill was used in a Gym battle against Ash's Snivy. It was easily able to block all of Snivy's attacks and then knock her out. Next Ash used Roggenrola. Thanks to its AbilitySturdy, Roggenrola could avoid being knocked out by Excadrill's Horn Drill. Later Roggenrola evolved into a Boldore and defeated the Subterrene Pokémon with its newly learned Rock Blast and Rock Smash attacks, despite being at a major disadvantage.
The Driftveil Gym appeared in Mine Mayhem and Underground Showdown, where Black challenged the Gym. Due to all the Gym Trainers being away at the time, Black was able to reach Clay at the bottom floor of the Gym without any difficulty. During the Gym battle, Clay told Black how he had heard of him from the other Gym Leaders, and how he had some time ago discovered the Dark Stone while digging at the Desert Resort. While battling Clay's Excadrill, Black's Nite accidentally sent a rock flying at the power box, shutting off the lights. This gave Clay's last Pokémon, Krokorok, an advantage over Black's final Pokémon, Costa, as it had the ability to sense the body heat of its target, even in the dark. Using himself as a decoy, Black gave Costa a chance to attack and defeat Krokorok, winning the match for him and earning him his fifth Badge.
Pokémon used in Gym
Krokorok is Clay's second known Pokémon. It was first seen guarding the Dark Stone along with Clay's other Pokémon while being spied on by the Shadow Triad. Later, it was used to battle Black in a Gym battle and was defeated by his Costa.
Excadrill is Clay's first known Pokémon. It was first seen digging up a mysterious stone at the Desert Resort. Later, it was shown guarding the Dark Stone along with Clay's other Pokémon while being spied on by the Shadow Triad. Later, it was used to battle Black in a Gym battle and tied with his Nite.
Palpitoad is Clay's third known Pokémon. It was first seen guarding the Dark Stone along with Clay's other Pokémon while being spied on by the Shadow Triad. Later, it was used to battle Black in a Gym battle and tied with his Musha.