Frog Mario

"Oh me, oh my! You've been transformed! Shall I change you back with this wand?"

- Kings

Frog Mario is an alternate form of Mario and Luigi that can be attained by acquiring a Frog Suit in the game Super Mario Bros. 3. This form improves their underwater mobility but hampers their movement on land by only allowing them to move in short hops.

Super Mario Bros. 3
In Super Mario Bros. 3 and its following remakes, Frog Mario can swim faster than regular Mario, allowing him to overcome currents in his path. Controlling Mario while swimming is also easier, as he can stop instantly, in a single spot in the water, and swim in any direction. However, Mario's on-land mobility is greatly decreased, and he cannot crouch or Slope Slide. This makes it impossible to complete certain levels, particularly Fortress Levels, as there are sections that players need to crouch to pass. He can only hop on the ground like a frog (though he can walk and run while carrying an item, such as a Koopa Shell). As such, Frog Mario's jumping ability is greater than regular Mario's. The Frog Suit will also prevent the player from slipping on Ice Blocks.

Super Mario Maker
Frog Mario also appears as one of the unlockable Mystery Mushroom costumes in Super Mario Maker. Weird Mario may appear in this form if a Warp Door is knocked in Edit Mode in the Super Mario Bros. 3 style.

Super Mario Maker 2
The Frog Suit was added to Super Mario Maker 2 in the version 3.0.0 update as the Super Mario Bros. 3 game style's second unique power-up. In addition to its improved underwater mobility, it grants the ability of running on water while carrying an object if the P-Meter is maxed out. The Frog form also has improved hopping controls and speed, and it can now crouch and slope slide. In multiplayer, Frog Mario is red, while Frog Luigi remains green. Frog Toad is blue with a beige spot on each side, while Frog Toadette has the same appearance, but magenta with her pigtails shown. The character's Frog Suit's expression changes for certain poses, such as closing its eyes while crouching, having angry eyes when running or jumping with an object or player, and its pupils looking up when carrying a player without running, much like the Frog Mario costume from the original Super Mario Maker.

The Weird Mario Easter egg from the first game also returns.

The Adventures of Super Mario Bros. 3
In The Adventures of Super Mario Bros. 3, Princess Toadstool and Toad were also able to use the Frog Suit. King Koopa also used this form through the use of a Power Pendant in the episode "Super Koopa".

Paper Mario: Sticker Star
A form of Frog Mario appears in Paper Mario: Sticker Star when a Frog Suit sticker is used; it only overlays the sticker onto Mario, rather than turning him into Frog Mario. With this sticker, Mario can dodge enemy attacks by jumping, and his jump attacks are also stronger, though only for one turn.

Paper Mario: Color Splash
Frog Mario appears in Paper Mario: Color Splash, via use of a Frog Suit card. It works like it did in Paper Mario: Sticker Star, letting Mario jump over enemy attacks. It now lasts until Mario takes damage (this physically removes the Frog Suit, as in Super Mario Bros. 3) or wins the fight.

Trivia

 * Early concept art for Super Mario Bros. 3 shows that Frog Mario would be able to use his tongue to slurp up and spit out enemies, which would later become one of Yoshi's abilities in Super Mario World.
 * In the Super Mario Mash-Up Pack in Minecraft, Iron Armor is replaced by a Frog Suit.