The fake Shadow Blot is the lookalike version of the real Shadow Blot and acts as the semifinal boss of Epic Mickey. Depending on which path the player takes, the fake Shadow Blot can either be erased from existence with thinner or redeemed with paint. The fake shadow blot is a Heartless ghoul in servitude to the Dark Spawn.
The fake Shadow Blot was created after the real Shadow Blot was trapped in the Thinner Bottle atop Mickeyjunk Mountain by Oswald and Ortensia. Unfortunately for Wasteland, the seal was not completely sound, leading to drippings of the shadow creature to escape the entrapment. These drips formed into Blotlings. The largest of these was the fake Shadow Blot, who was subsequently the most powerful and often mistaken for the real Shadow Blot.
The fake Shadow Blot then took over the real Shadow Blot's role as leader of the lesser Blotlings, and eventually usurped power from Oswald. Seeing that this new entity would help him achieve his goals, the Mad Doctor allied himself with the new ruler, abandoning the now alone Oswald. Eventually, after a period of degeneration in the ravaged Wasteland, the fake Shadow Blot somehow was able to temporarily leave the Wasteland (although his lower half was still chained to the world), travel through Yen Sid's mirror, and drag Mickey into the retired cartoon world in order to steal his heart and permanently free his master (the real Shadow Blot). Their plan fails, however, when Mickey escapes his bonds. The fake Shadow Blot immediately gets between the mouse and the Mad Doctor, but flees when Mickey raises the magic paintbrush.
For most of the game after this, the fake Shadow Blot works behind the scenes, organizing and commanding the Blotling army. This remains the case until Mickey and Oswald gather the parts for a rocket to escape Wasteland. It is then that the fake Shadow Blot leads the entire Blotling army up Mickeyjunk Mountain, as a full-scale attempt to free their master. Mickey, Oswald, and Gremlin Gus meet the challenge, scaling the mountain to strike down the freeing of his master (the real Shadow Blot). As Oswald desperately tries to keep the bottle prison corked, Mickey faces the fake Shadow Blot in battle at the summit.
The fake Shadow Blot's boss battle strategies for using either paint or thinner are the same, besides the weapon of choice. At the first time he will throw some thinner at you, which you can avoid it easily. Spraying Thinner or Paint will do nothing. He will then charge some thinner on both of his hands and fly high away. He will shoot some thinner from above repeatedly. After that he will drop himself into the ground (you can see his shadow on the ground to avoid him), trying to inhale you, same as by Slobbers. This is the chance where you can spray him with Paint or Thinner. You will notice that he will be covered by some Paint or Thinner. Now, he is able to summon some Spatters. They're annoying, try to get rid of them quickly like use your Spin Move to knock them out of the cliff. The fake Shadow Blot also become more powerful as he can throw thinner more faster than before, especially when he's flying above you. Sometimes he will also try to knock you out. Keep avoiding his Thinner shots and you'll win the battle.
Erasing with Thinner
If Mickey decides to battle the Blot with Thinner, he must slowly erase the villainous commander. Mickey is eventually successful and the Blot melts away, clawing at the ground as he fades. The Thinner battle earns Mickey the Shadow Boxing pin.
Befriending with Paint
If Mickey chooses paint as his weapon, the heroic mouse must slowly but surely cover the beast in blue, while avoiding his attacks and underlings. Once finished with this, the Blot rises into the air and blows all of the paint off of himself in an energy blast; however the paint had already soaked into his core, changing his character. Now friendly, the fake Shadow Blot lifts Mickey into the air and tickles and cuddles him affectionately. Gus quaotes," He's actually kinda... sweet." He then flies off in a wave, assumed to be departing for a new life in the Wasteland. This makes the fake Shadow Blot the last surviving Blotling in this scenario, albeit a reformed one. This version of the battle earns Mickey the "Me and my Shadow" pin.
Role in the series
The Shadow Blot and his fake underling are unofficial characters, not planned to appear in the series at all.