"Tough as nails" (French: Vernis mon beau vernis) is the fourth episode from Season 4 of Zig & Sharko, and the two hundred thirty-eighth episode overall. It is written by Mathilde Belin and storyboarded by Guillaume Picard.
While Marina and Sharko are doing the gardening, Bernie notices that Marina's nails are very dirty, so he tells her to get a manicure. It's all part of Zig's plan, though. Marina refuses, but Sharko gets interested of getting his nails decorated, so he went to the nail dressing area. Zig didn't notice that it's Sharko who's sitting there, and then gets punched mid-air. Bernie then applies nail polish to Sharko's nails.
He then showed it to Marina, which she gets impressed, so she wanted to hand him over carrots (with dirty nails), but Sharko is afraid that the nail decorations might wear off. Zig will take advantage of it.
Zig then sets up a rock-climbing wall, and Marina wants to try it. She uses her feet to climb up the wall, which frightened Sharko as it might destroy his nail polish. What we see is Marina climbing up, but in fact, she's getting reeled by Zig. Sharko tries to climb up, but he's afraid that it might ruin his nails, so he grew hands on his buttocks, and proceeded to climb up. Zig thought that he's reeling Marina, but he reels Sharko instead, resulting to him getting thrown in the volcano. They then celebrated after reaching the top, and Marina high-fives Sharko, but then got his nail polish destroyed in the process. So he went back to the nail dresser.
After Marina fixes a broken down vehicle, Sharko shows her new nail decorations, which almost blinded her. Zig catches Marina's attention with the soccer ball, and then sets up a match against Sharko. Marina kicks the ball. Being afraid that it might get ruined again, Sharko hid his arms and legs, and took a hit at the head. After that, Zig brings out a soccer ball dispenser, and attempts to eat Marina, but he failed after he was launched with the soccer balls in the goalie. Everyone celebrates...until a piece of confetti lands on one of Sharko's nails, resulting to ruining his nail decorations once more. He goes back to the nail dresser once again.
While Marina is playing the ukulele, she gets stunned at Sharko's nail extensions, breaking one of the ukulele's strings in the process. Marina's attention gets caught again by Zig, who is playing bowling. She then bowls using her feet, and after hitting a strike, the bowling ball lands on Sharko's head. The chasing sequence then begins.
Zig enters the gym, and locks the door, which Sharko bumps into it. Sharko sacrifices one of his nail extensions to unlock the door. The chase continues with Sharko hopping, while Zig runs over the barbells, which Sharko deflects, resulting to all of his nail extensions on his feet to break. The chase further continues to the elevator, which he bumps into it, and more of his extensions broke, leaving two more of it. He then uses one of it to act like it's a carpenter's saw, breaking it in the process. He drops down to the storage room. Zig stops running during this encounter. Sharko then uses his last nail extension and acts it as a sword, and then Zig brings out a nail clipper, leaving Sharko in strong fear. It is now Sharko who's being chased by Zig. During the sequence, he saw the sandwich getting drawn nearer to the pot, which frightened Sharko even more, resulting to him getting hit by the nail clipper and dropped down. Sharko uses the final extension to hit the pipeline's faucet and Zig gets hit by it, and then gets dropped into the soup that is being prepared. The sandwich flew over, opens, and then Marina saw Sharko crying after he lost all of his nail decorations.
Back at the ship, Marina gathered some seashells and placed it onto Sharko's nails, acting as decorations. The episode then ends.
