Frog

Frogs are a type of real-world creature found in the Mario franchise, in which normal frogs exist along with anthropomorphic frogs who are sentient and are capable of speech.

Super Mario RPG: Legend of the Seven Stars
The Tadpole Pond is inhabited by large, sapient frogs in the duration of Super Mario RPG: Legend of the Seven Stars. Mallow was raised by the frogs (specifically Frogfucius) and believed that he, himself, was a frog as well. The young tadpoles comprise a greater part of the population than the frogs, of which there are only two.

Yoshi's Story
Frogs also appear as enemies in Yoshi's Story during Stage 4-4: Neuron Jungle. They swarm any Yoshi crossing the lagoon. Although any Yoshi can eat them, Green Yoshi likes them best.

Diddy Kong Racing
In Diddy Kong Racing and its remake, several frogs live in the pond in the hub. One of these frogs, who has a tell-tale red crest upon its head, is actually Drumstick, who has been put into frog form by Wizpig. He can be freed if the player runs over him in a car.

Luigi's Mansion: Dark Moon
Frogs appear again in Luigi's Mansion: Dark Moon. In this game, they are pigmented with warm colors, ranging from vermilion red on their body skin to yellow on their webbed toes. They croak when discovered and act as ambiance creatures. They do not actively try to injure Luigi, but can drain five heart points from his health meter if they run into him. They can be defeated with the Strobulb, dropping a Coin once they disappear.

The Frogs are mainly found in the Haunted Towers. They also show up in the final King Boo battle, with special giant versions of the regular frogs appearing as well, which may spawn from spiked balls after King Boo slams the ground. These giant frogs, however, do not grant any treasure upon getting flashed with the Strobulb.

The game also features a more precious variant of frogs called Gold Frogs, which reward Luigi multiple Gold Bars if he uses the Strobulb on them. Gold Frogs can be primarily found on the East Balcony of the Treacherous Mansion.

Super Mario Odyssey
Frogs appear in Super Mario Odyssey, where they can be found in Bonneton, Honeylune Ridge, and the Darker Side. They can be controlled by Mario and Cappy and are also the first capture found in Super Mario Odyssey. When captured, frogs give Mario the ability to jump higher and shaking the Joy-Con causes Mario to perform a High Jump, allowing him to reach even higher placed platforms. Sometimes before being captured, they wear small top hats. A plush frog is also a souvenir for the Cap Kingdom. According to the Moon Kingdom brochure, the frogs there were brought by the Moon's first pioneers; seeing a "Moon Frog" is said to be a good omen.

Trivia

 * In an E3 demo of Paper Mario: The Thousand-Year Door, Hooktail had a strong dislike toward frogs, but this was changed and Hooktail was given the hatred of crickets. However, she is still afraid of frogs in the translated versions of the game other than English.