We've moved! http://jorellisisland.blogspot.com
Canon Immigrant (n.) - a character created and nurtured in another medium and, eventually, imported back into the original. (from tvtropes.org)
In other words, a canon immigrant is a new element that's introduced in the adaptation of a piece of work that proves popular enough to be added to the original work. As comic books have been adapted into other media for as long as they've been around, and since many of those adaptations were more popular than the comics themselves, canon immigrants in comic books are everywhere. But, for whatever reason, there's not a single place to look that catalogues them all. There are sites all over the internet that talk about the phenomenon, but none of them offers a definitive list, much less provides information like dates of first appearance.
This site plans to change that. Inside will be an extensive list of all of Marvel and DC's canon immigrants, with as much information as can be provided - first appearances, pictures, etc. But unlike the narrow definition that TV Tropes uses, this site will document anything that first appeared in a non-comics medium: costumes, names, slogans, and settings are just some examples.