Pump Mario

Water Mario is a quasi-form taken on by Mario in the Mario & Luigi series. This form first appears in Mario & Luigi: Superstar Saga, where it is mainly used on Hoohoo Mountain. When Mario drinks from certain fountains, he gains this form, in which he is extremely bloated and heavy, to the point of not being able to jump, due to being filled with water. Luigi can use the High Jump on Mario to flatten him and make him spit all of the water out at once, relieving his brother of this form. The water stream released can be used to douse small flaming statues, causing masks on the wall to spit out Whirlwinds, as well as dousing other, smaller fires and operating fan-like devices. Later, when Mario and Luigi obtain hammers, Luigi can hit Mario with his hammer to make him shoot out small, long-ranged spurts of water up to three times per drink. After gaining the Thunderhand ability, Luigi can also tickle Mario, causing him to spit out all the water in front of him, which can be used to water plants. If Luigi attempts to drink the water himself, he will spit it out instead of becoming filled. Mario can also take on this form when he has his passport photo shot as one of the poses. He also uses a similar form after swallowing the Chuckola Reserve; Luigi later performs a High Jump on Mario to make him spit the soda into Queen Bean's mouth.

In Mario & Luigi: Partners in Time, only Baby Mario can use this ability, on Yoshi's Island, with the form being called Baby Pump in the Super Mario-Kun manga. The form's mechanics have changed slightly. Since the ability to High Jump cannot be used by Baby Mario and Baby Luigi alone, Baby Luigi can only hit his brother with his hammer. Additionally, up to ten shots of water can now be collected at once, depending on how long Baby Mario stands in front of the fountain. The ability is now mainly used in cloud areas, where the water is shot into curved pipes that send it to the ground below to put out fires.

The ability returns again in Mario & Luigi: Bowser's Inside Story, where it is again used by Mario, with help from Luigi. In this game, Mario does not learn how to become Water Mario until he reaches Peach's Castle, meaning that it is one of the last abilities learned. The ability's mechanics are essentially identical to in Mario & Luigi: Partners in Time, and Mario can hold up to ten shots of water at once.