Okay, so after watching more Mole Mania playthroughs, I think I can make a decent set of Special moves for him.
His Neutral B could 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.
His Side B will be the Barrel Roll. This one was a bit of a stretch, seeing as Muddy never actually did this. However,it is creative liberty, I guess. Muddy pulls out a barrel that he uses in his game, and hops on top of it. He then speeds forward on the barrel to ram opponents. Can be a decent horizontal recovery.
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.
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 Sundes. Another forum user gave me this idea. Sundes was a sun-based boss in Mole Mania, as the ruler of Level 2. One of his attacks involves him going supernova, so Muddy needed to get out of the way to survive by going underground. Once Muddy has the Smash Ball, he'll adjust his Sunglasses and go underground. Sundes would then appear, and go Supernova, sending a vast fiery wave across the stage. If hit, the opponent will take major damage and good knockback. It can, however, be avoided by some characters with high or multiple jumps. Muddy will the resurface and continue fighting.
Complete moveset coming soon. Feel free to comment.