Chuck

Chuck is one of the main protagonists in "Help! I'm a fish". He is 12 years old and a computer nerd. He's also Fly and Stella's cousin. Chuck is revealed to be an excellent fighter as he knocked out all the piranhas near the climax of the film on his own.

Help! I'm a fish
Chuck does very important work on his computer, but Fly accidentally deleted it. He had a backup, but when he was going to wake his mother (who had fallen asleep), Fly grabbed the backup and told him he was coming fishing with him and Stella, or he would break it. They ended up at Professor MacKrill's home and he introduced them to the fish potion. After they had searched for Stella and Fly was about to throw a starfish (Stella) out of the window, Chuck tried to run and stop him, but he was unfortunately too late. Fly had just let go, and immediately right after, they rowed out in the ocean to find her.

Fishy adventure
After Fly jumped aboard, the storm got worse, and in order to survive (since he could not swim), Chuck was forced to drink the potion, and he became a jellyfish. When Fly and Stella met him, he had already been looking for them, turning the enjoyment as a fish into a time-limited quest to find the antidote and return to being humans within 48 hours or else they would remain fish permanently. Chuck was usually the negative one in the group, but after Fly had been deadly wounded by Crab, he took command and proved to be a good cousin to have. He calculated the road in the pipe leading to the professor's lab, and they got back to the lab unharmed. In order to escape the piranhas, Chuck tricked them into swimming into the vent, overflowing the lab. After Joe had taken the antidote, Chuck fought off the piranhas that escaped the vent. When Fly came back with the antidote after tricking Joe into drinking all of it and drown, Chuck and Stella drank a good bit of the antidote, and later, when they were human, they thought Fly was dead, but he had also become a human again.

Human again
Chuck, now a much more fun guy since the adventure under water, invented the water-slide with the professor and later, after seeing how glad Stella was when Sasha came back to her, talked with the professor and they turned Sasha into a real horse.

Appearance
As human: Round, gray jacket, teal shirt, blue tie, round glasses, black pants, brown shoes, black hair

As Jellyfish: Blue jellyfish, water-proof clock (later in the film)

Both: Glasses.