The Wind-Up Mr. Froggins is a toy introduced in Nintendogs + Cats along with Sir Nibbles and Miss Chickie. It replaces the Wind-Up Toy from Nintendogs. It is a green frog with a yellow wind-up handle that makes the toy hop along with a "Boing" sound. It can be bought from the Town BARC shop from the beginning, for only $8.
3DS US: "Just look at Mr. Froggin's sly smirk. Wind him up and play!"
3DS UK: "Don't be fooled by Mr Froggins's dopey air. Wind him up and play!"