Watt

"You just saved me like a hero! You're a hero, aren't ya? You're the coolest!!!"

- Watt

Watt is a female baby Li'l Sparky and Mario's sixth party member in Paper Mario. Although Watt's age is unconfirmed, it would appear that she is a young child because of her pacifier. Her Super Paper Mario Catch Card description also implies that she is young.

Paper Mario
Mario finds Watt while traveling through Shy Guy's Toy Box. He eventually comes to a dark room inhabited by the Big Lantern Ghost. The battle against the ghost involves attacking the lantern he carries to make the room brighter, and after his defeat Mario can break open the lantern and find Watt inside.

Watt explains to him that the Big Lantern Ghost had kidnapped her and trapped her in his lantern. She tells Mario that she heard some of the Shy Guys talking about him, and she volunteers to join him and his party on his quest. Watt's field ability allows Mario to hold her like a lantern, illuminating dark places and allowing him to find invisible boxes and items. Watt's main attack also has the ability to automatically override an enemy's defenses, making her a valuable partner in many battles.

Later in the game, the player can find two letters in the Toad Town Post Office, one from her mother and another from Fuzzipede. At the end of the game, she is conversing with a group of Shy Guys, and she appears to have befriended them.

In the Japanese version of Paper Mario, Watt speaks in a baby-like way that turns "sh" sounds into "ch" sounds. For example, ureshii desu (Happy) becomes urechii dechu.

Tattle
Goombario can use Tattle on a lantern holding Watt only after Mario defeats the Big Lantern Ghost but before Mario breaks the lantern to release Watt.
 * "Say... This is the lantern that belongs to the Big Lantern Ghost. There's something inside. Do you think it'd come out if we broke it?"

Paper Mario: The Thousand-Year Door
Like the rest of Mario's partners from the first Paper Mario, Watt was going to appear in some fashion.

Super Paper Mario
In Super Paper Mario, Watt appears as a Catch Card that could be found in the Flopside Pit of 100 Trials. She could also be seen very briefly at the beginning of the game, where she, along with all the other partners in the Paper Mario series could be seen in a photograph at the Mario Bros.' House.

Super Mario-kun
Watt appears also as one of Mario's various partners in the Paper Mario arcs of Super Mario-kun. Unlike in the games, Mario and his partners scare away the Big Lantern Ghost by removing its robe. Mario then breaks the lantern with a hammer to reveal Watt inside.

Watt's family
Watt is known to have a mother, who is unseen and unnamed. Watt speaks of her occasionally and even receives a letter from her in the Toad Town Post Office. Though her mother is mentioned several times, no mention of Watt having a father is ever made.

Catch Card
Card Type: Rare Card Description: This is Mario's good buddy Watt from Paper Mario. This guy was pretty bright for his age!

Paper Mario

 * Start Menu description: The child of Li'l Sparky, she can produce ample electricity. Press to illuminate areas and see invisible blocks. She's great at penetrating defenses and paralyzing enemies.
 * Official Nintendo Player's Guide bio: After you save Watt, the captive of Big Lantern Ghost in Shy Guy's Toy Box, she can shed light on your adventure. By holding her, you can have her light up a dark room or reveal hidden blocks. She attacks enemies with minimal physical contact, making her useful against some spiked and electric enemies.

Trivia

 * Watt is one of the only characters in Paper Mario that is capable of dealing damage to Bowser after he powers himself up with the Star Rod (during the first round of the final battle). However, she is only able to do one HP worth of damage to him. The same thing applies to Lakilester.
 * Although she is female, Watt is mistakenly referred to as male on her Super Paper Mario Catch Card, and during her Super Block upgrades.
 * Watt has different responses depending on how the lantern is broken.
 * "Hm hm hee hee...Yay! I got out! Yay for me! Thanks, mister!" if smashed.
 * "Cough cough... You're crazy, mister! Did ya have to, um, blow it up to get me out? Jeepers!" if detonated.
 * There is a major glitch in the US version of the Nintendo Switch Online version of Paper Mario that causes the game to crash if Mario gets a Game Over with Watt as his partner. In other versions of the game, the screen flickers briefly.