From the Super Mario Wiki
A Scaredy Rat is a white rat creature that first appeared in New Super Mario Bros. Wii. They appear to have black sclera, red pupils, orange feet and huge buck teeth. They slightly resemble Little Mousers. Their name is a pun on the term scaredy cat, which is a childish term for a coward.
Super Mario series
New Super Mario Bros. Wii
Scaredy Rats as they appear in New Super Mario Bros. Wii
Scaredy Rats appear in the game New Super Mario Bros. Wii where they are found in Ghost Houses. They are troublesome and run quite fast. When Mario or a teammate approaches, they stop scuttling and start jumping in place. When the player leaves, the Scaredy Rats continue scuttling. If one is stomped, all nearby Scaredy Rats will run in panic.
New Super Mario Bros. U
Scaredy Rats reappears in New Super Mario Bros. U with the same features of New Super Mario Bros. Wii. They also appear in the dark where their eyes shine like a Swooper.
Mario Party series
Mario Party 9
A Scaredy Rat appears in a Captain Event known as Scaredy Rat Race in the portal-like tower near the final area of the board Boo's Horror Castle. The Scaredy Rat steals some Mini Stars from each player and scuttles each turn some spaces ahead using a dice block. The current captain has to choose a player who must roll a Dice Block. The player who actually reaches the Scaredy Rat defeats it and receives all the Mini Stars the Scaredy Rat has stolen.
Mario Party: Island Tour
A Scaredy Rat can be seen on the Banzai Bill's Mad Mountain board in Mario Party: Island Tour. They also appear in the minigame Rat-a-tat Flat, which involves players having to Ground Pound the Scaredy Rats that appear to earn points.
Paper Mario: Sticker Star
Scaredy Rats make their Paper Mario debut in the Nintendo 3DS game Paper Mario: Sticker Star as enemies in The Enigmansion of World 4. They maintain their appearance from New Super Mario Bros. Wii. In battle, Scaredy Rats can do two attacks. Their main attack is jumping on Mario. However, if a Scaredy Rat runs in place before attacking, it will steal one of Mario's stickers. Mario can get his sticker back by defeating a Scaredy Rat before it flees with the sticker. Blocking this attack does not prevent the Scaredy Rat from stealing the sticker.
Names in other languages
|Squeak-Squeak (from 「ちゅう」 chuu (sound made by mice))
||Pormanteau of rata (rat) and atacante (attack)
||Pormanteau of aterrador (frightening) and rata (rat)
||Pormanteau of Souris (mouse) and Boo
||From "ratto" (rat)