That's right: From June 3 to July 2, there'll be a post each day highlighting Teenage Mutant Ninja Turtles canon immigrants. Now, because TMNT canon is a little confusing, it can be hard to tell what counts as a canon immigrant and what doesn't. So for the purposes of this blog, a TMNT canon immigrant is anything (a) from the movies, cartoons, video games, toy lines, or tie-in comic series that later appeared in (b) TMNT volumes 1, 2, or 4 [because they're by the original creators] or TMNT volume 5 [because the original creators are involved, it's the new official continuity, and its goal is to use as much of the diverse TMNT lore as possible].
Man Ray first appeared in Teenage Mutant Ninja Turtles Adventures #5 (September 1989), the first issue not to adapt one of the cartoon episodes. He would later join the Mutanimals.
To be thorough, I should also mention that his first appearance MAY be in a series of mini-comics released with Ninja Turtles cereal. I know they were released in 1989, but I don't know if that's before or after the above issue. But for the record, he appeared in mini-comic #3 (#2 features the first appearance of Wingnut):
Man Ray would later go on to cameo with (most of) the rest of the Mutanimals in Mirage's Tales of the TMNT #58 (May 2009), although it's important to note that this is still the "animated" version because it's in a scene of the multiverse.
Man Ray is one of the only Mutanimals to make the jump to the IDW continuity, although there, he's usually just called Ray. He first appeared in Teenage Mutant Ninja Turtles: Mutanimals #2 (March 2015).