Clark Still is one of the playable characters since Metal Slug 6.
"Hey, Come on!!" -Clark's pet phrase.
It seems that he joined the mercenary squad some years ago, but nothing else is known about Clark other than that. He and Ralf have long been brothers-in-arms, and they always go to battle together. Just like Ralf, there are also countless rumors about his past, and they are all equally outlandish. However, the very number of these rumors and the known fact that he often joins Ralf in tournament fights offer a clue to his fighting prowess. On the battlefield his combat style somewhat differs from Ralf's, but he shows expertise in close quarters combat techniques all the same. Enemies unfortunate enough to run into him find themselves instantly flung into the air and crashing back down.
In Metal Slug 6 and Metal Slug 7, Clark is the most balanced character, having average stats on everything. Clark is also able to use his Argentine Backbreaker on common enemies, and he will be temporarily invincible after each hit. If he uses it in succession, the points will be multiplied, allowing for very high scores.
In Other Games
Metal Slug Defense
Originally a cameo on the POW list, he later appears as a playable unit alongside Leona and Ralf. His main weapon is the Iron Lizard and his special is throwing an explosive barrel, named the "Nageppanashi S.A.B." (which stands for Super Argentine Backbreaker).
Metal Slug Attack
In Metal Slug Attack, he appears as a placement image for the "Event Crank". As of 1.6.0, he's available as a playable unit, now with the upgraded ability to throw out 3 explosive barrels at a time (at varying distances). Just like Leona and Ralf beforehand, he was a pre-aquisition unit, then was available in the Medal/VIP crank, and, in later updates, can now can be bought from the POW Rescue Shop.
A new version of Clark named Jet Clark appears in the "Tough & Cool" event. Alongside a new set of clothes, Jet Clark has a completely different moveset. His close range attack is doing Ralf's Vulcan Punch (without the explosive effect), his Iron Lizard is replaced by a Heavy Machine Gun, and his special is throwing refrigerators that serve as barriers.
In both games, his voice is based on the King of Fighters rather than his Metal Slug incarnation.
- His favorite food is oatmeal.
- For unknown reasons, Clark and Ralf are never randomly picked to be the possessed mini-boss during mission 5 of Metal Slug 6.
- Both Ralf and Clark originally appeared in the Ikari Warriors series. In the U.S. and European versions of Ikari Warriors, they were renamed Paul and Vince, respectively. They both also appeared in the The King of Fighters game series, under their original names.
- Clark's sprite are actually edited sprites of Tarma.
- He is known as Clark Steel in old KOF games.
- Clark is the only character thus far to have temporary invincibility from a unique ability.
- Clark, Fio, Red Eye and Alisa are the only playable characters who wear a cap, with Clark being the only male playable character to do so.
- Clark is the only one of the Ikari trio to not make any presence in a mobile Metal Slug game prior to Metal Slug Defense.