His Neutral B would be the iron ball. Press B once, and it spawns, and stays on the ground in front of you. You can keep it there, and it will act as an unbreakable wall. However, if you press B again when you are close to the ball, you can throw it at your opponent! It will be very slow and not very powerful at first, but if you hold B, Muddy will charge up the throw, increasing the speed, distance, and damage. However, if the opponent hits you during start up, you will drop the ball. The ball will eventually disappear if A.) Too much time passes without you throwing it, or B.) You hit the opponent. Only one Ball can be present at a time per Muddy Mole. It does 15% when pushed forward with no charge, 22% when charged. Going backwards, it does 20% uncharged, and 30% when charged.
His Side B will be the Hole Trap. Muddy would crouch low, dig a small hole, and then be able to leave the scene. The foe wouldn't know where the pitfall spot is, under normal circumstances. When it is stepped on, they fall into a pitfall. Muddy cannot get trapped by this move. So yeah, it's the pitfall item, essentially. Muddy can have up to two of these out on the stage at any given time. 0%
His Up B would be the cabbage jump. After Muddy Mole defeats a boss in his games, he saves one of his children, who pop out of a giant cabbage that falls from the sky, and leap up with a corkscrew-like jump. Muddy would essentially do the same. A giant cabbage would surround him, and he'd pop out using a Wario-like Corkscrew. If used in Midair, the cabbage will fall to the ground, potentially doing damage, and possibly a meteor-smash. When used on land, it disappears after use. I guess you can call it a mix between Wario's and Sonic's. 16% with the corkscrew, 10% if the cabbage hits you.
Muddy Mole's Down B would be Burrow. Going underground was key in Muddy Mole's adventures, so naturally Smash should reflect that. He would dig a hole, and go underground. If used on a passable platform, he'd fall through it. While underground, he can move around very fast, but at the expense of not being able to see where he is. By releasing B, he will pop out of the hole, causing minimal damage. However, you only have a three second time frame to stay underground, otherwise you are forcefully removed from the dirt. This would make up for Muddy's lackluster aerial game.
Finally, his Final Smash would be the Mole Family. When the Smash Ball is obtained, Muddy whistles loudly. His children and wife appear by his side and burrow into the stage. Going with Muddy's theme of stage control, his family makes the entire stage shake with violent tremors. To make matters worse, if the foe gets hit by one of the descending moles, they will be put into a Pitfall state. Every two or so seconds, the tremors cause 6% damage to any foe on the ground. Tripping is also slightly more likely. The effect only lasts for 15 seconds, but Muddy himself is free to move about and perpetuate the foe's agony by keeping them grounded. After 15 seconds, the family emerges. Muddy's wife puts the baby moles in their wagon, and they disappear.