The Culprit

Jack has had some sleeping problems as of late. He wants to sleep in our bed and when we take him back to his bed, he starts to complain, cry and just say " I want Mami's and Papi's bed."

For awhile when this first started , we thought the culprit was Monster's Inc, the Pixar movie. Jack would say, There are no monsters in the closet or under the bed, and that was our clue that maybe he shouldn't see the movie. Even though it is cute, think about it, the premise of the movie is that monsters get their kicks out of scaring kids. We banned that movie , and he has not seen it in a long time. Which we thought that would take away the idea of monsters in the closet, but lately with Jack wanting to sleep in our bed more and more, he has claimed a new culprit that has been added to his fear of the night list.

Diesel 10 - a character from Thomas the Tank Engine.
This character is just mean, and in every episode that he is in, he is calling out the other engines "Spotty Boilers, Ratty engines, Stinky Steamies." All the while he growls every time he sees them - GGGGRRRRRRRRRRRRRRRR!!!!!!!!!!

Jack never liked this character, but we would always tell him that Diesel 10 was just being silly and in the end, he would help out Thomas. Even when we would play, I would give Diesel a nice tone of voice. A c0uple of days ago, I asked Jack why he insisted on coming to our bed. He said cause Diesel 10 is there.
The countless episodes of Diesel growling is in Jack's head. How do you get out a bad idea out from a child's memory? We can tell Jack over and over again that Diesel is just a silly guy, he is not real, that he has a silly face. But that tiny fear that Jack has had toward this character since he was little is just there, and it doesn't go away.
At this point, Brian and I are not sure on what to do, and what is right and what is wrong when it comes to something like this.