So after thinking about it for a day I've narrowed down the list of characters and finally chosen who the heroes will be, why I chose them, and what position they'll have on the team, and this is the list.
Mr. Peabody - Leader, His ingenuity is key to leading the team to victory. He's got a rivalry with Puss in Boots because of their animal instincts and often sword fight. He's altered the WABAC to travel dimensions and bring heroes from each of them.
Hiccup and Toothless - 1st half of the Flight Team, They rule the skies and take down enemies that the other team members can't reach in the air. Hiccup's gotten to be good friends with Jack Frost but Toothless hates him because Jack keeps freezing the tip of Toothless' tail to get back at him for being shot at when they first met.
Tigress - Her Kung Fu fighting makes her an incredibly hard opponent to beat and a fearsome threat to her enemies. Po would of been taken as part of the team but not knowing that Peabody was bringing heroes to his dimension she blocked Po from being taken and instead was taken herself. She extremely dislikes Puss in Boots because he constantly flirts with her.
Megamind - A mastercraft with weapons, Megamind develops all of the equipment and technology that some of the team uses. He's become a colleague of Peabody's because of their genius minds and inventive ways.
Puss in Boots - A master sword fighter. This heroic thief was chosen above other from his home because while his friends have settled down with their families, Puss has always kept on looking for the next adventure that comes his way and become a greater hero. He has an attraction to Tigress that annoys her but his determined nature makes him keep trying.
Jack Frost - A wielder of Ice and Snow and the 2nd of part of the Flight Team. It was hard to decide only one guardian out the five but when it came to who would stand out the most, powerwise, Jack was the clear choice.
Susan/Ginormica - The "muscle" of the team. Come on, how could I leave out a 50 foot woman who can crush virtually anything around her.
Eep Crood - The "savage" of the team. She a tough cavegirl but she's gotten tougher after the events of the movie and has some new tools and weapons at her disposal. After Eep is brought along with the other heroes, she gets amazed at everything futuristic she sees no matter what it is or how normal it is to us.
Theo/Turbo - The "speed" of the team. Turbo is the smallest guy of the group but he doesn't let that effect his importance. Since being brought with the others his speed has tripled and he's even started come up with some new tricks that would come natural to a speedster like him
So that's my line up. What do you guys think ?