The Super Hero Squad Show was a self-aware parody of Marvel comics aimed at children that aired from 2009 to 2011. On a personal note, it helped establish my love of Marvel and its characters. One of the main members of the titular team was Reptil, a relatively obscure character from the comics who can transform part of his body into part of a dinosaur's body. Given his first appearance in the comics was around the time when The Super Hero Squad Show was being developed, was he created with the intent of appearing in the show? If not, why was such an obscure character chosen to fight alongside the likes of icons such as Iron Man, Hulk, and Wolverine?
There are several wiki sites that claim Reptil was created for the TV show, but I can't actually find a valid reference for that.
In terms of first publication, that appears to vary by source, probably not helped by the fact that Reptil's first main universe appearance was Avengers: The Initiative Featuring Reptil (March 2009) and his first Super Hero Squad Appearance was in the tie-in comic Super Hero Squad: Hero Up! (also March 2009).
Reptil appeared in the actual Super Hero Squad TV show a few months later in the episode To Err is Superhuman (first aired in October 2009).
The first Marver Super Hero Squad Reptil figurine (the toy line that spawned the cartoon) came out with wave 18 in January 2010.
Whatever medium Reptil was first created for, Marvel appear to have been banking on him from the start, this appears to be backed up in a media article from March 2009 that quoted marvel as billing Reptil as "the next big thing".
So to sum up, Marvel had a new character which they believed would be a huge hit and just threw him into everything at more or less the same time.