100 Deeds for Eddie McDowd/WMG

The Drifter is not planning to turn Eddie back to normal.
Well, why do you think he minuses his good deeds just because he can do whatever he wants?

The Drifter is Eddie's Split Personality.
He is created by the good left in Eddie since he's a kid shown in A Very Canine Christmas. If he has completed 100 good deeds and Eddie turn into a human again, the Drifter will merge with him.

Eddie is in a dream or coma in the entire series.
Must have been taken place after being traumatized by Justin spilling milk on him.

The Drifter must have caused the explosion in a car.
Well, for starters, Eddie throws too many rocks and the car didn't explode. As a result, the Drifter uses his powers to cause an explosion and berate Eddie for this as if it wasn't his fault.

The Drifter is a Reality Warper.
He didn't turn Eddie into a dog; instead, he just make him think he did so that he can do good deeds. He also did this to Justin and the entire world so that his Masquerade will not fail.

The Drifter is one of the spirits in Brother Bear.
Well, does it look familiar when he turned Eddie into a dog as a symbolism of the animal he almost killed?

The Drifter turned Eddie into a dog to create a dragon.
He turns bad people into animals as punishment for their misdeeds, but he has a hidden agenda to that. The goal is to find anyone who is bad enough to be transformed. Eddie is going to be his general. Once Eddie does 100 good deeds and turns back human, the Drifter will offer him his parents back, and gives him a choice: join him or act against him.

The show is All Just a Dream for Eddie.
Ever since being spilled milk all over accidentally by Justin, he's been traumatized by this experience that he is put in a coma for this. Therefore, everyone are aspects of himself.
 * Himself = his Self/Ego
 * Justin = his Id
 * Gwen = his Super Ego
 * The Drifter = his conscience and dark part

The Drifter turned Eddie into a dog so that he could kill him.
It seems to me that ever since someone before Eddie manages to do 100 good deeds and turn back human, the Drifter has gained a conscience for his experiences and thinks that the world would be better off without him since he is bossed around by the Drifter Council. He needed someone who could hate his guts long enough to kill him; therefore, tries to commit suicide by human turned animal.

The Drifter erased Eddie's parents existence because they were holding him back.
It would appear that his parents could are considered to be his Morality Chain. In other words, they're the reason why Eddie remains good despite all that bullying he did at school. Realizing this, the Drifter has erased them, thinking that they're distracting him. Unfortunately, since they're the source of Eddie's goodness, bad move. Once Eddie turns back human, he'll get revenge on the Drifter for this.