I had a similar idea a few years ago (I even made a Fantendo article about it and a crappy fan art!): https://fantendo.fandom.com/wiki/Dog_MarioMy idea for a Super Mario power-up is the Super Collar. The Super Collar gives you the Dog Suit. In the Dog Suit form you have five moves: Dig; which allows you to excavate power-ups, items, coins or collectibles. Bite: which lets you attack enemies or grab and throw objects. Bark which stuns regular enemies and scares cat enemies. Howl is used to attract stray puppies, Chain Chomps and Yoshi's pet dog Poochy. Smell; Smelling allows you to see different footprints of different animals depending on shape and color. If while smelling you follow white paw prints to a glowing spot and dig there you will get the Wolf Bone. The Wolf Bone is a secret power-up that gives you the Wolf Suit. The Wolf Suit has a few tweaks such as more movement speed, an attack boost, non-slip ice walking and the ability to swim underwater and the ability to sense secret collectibles known as Wolf Moons. Howling stuns any enemy that is close to you and turns puppies into wolves. If you find a dog house with white paw prints, howl until Polterpup shows up.