As far as cosplay goes, you would be hard pressed to find a pair of characters more popular than Wolverine and Batman.
But what of Dark Claw, the Wolverine/Batman mash-up that actually appeared in legitimately published comics? That is less common.
The costume is a lot of work, and does not come with as much pre-fab parts as the classic Batman and Wolverine looks. But, as one DragonCon attendee proved, the effort can be well worth it.
Dark Claw was created by Larry Hama, Jim Balent, and Ray McCarthy and first appeared in Legends of The Dark Claw #1 (after a brief cameo in Marvel vs. DC #3), one of the Amalgam Universe comics produced in connection with Marvel vs. DC in 1996.
Marvel vs. DC (also titled DC vs. Marvel; the pair traded off) pitted the heroes and villains of the Marvel and DC Universes against one another in order to appease mad gods who represented each reality and wanted to wipe the other from existence. Along the way, the Amalgam Universe was created, smooshing together heroes from both worlds to get combinations like Super-Soldier (Captain America and Superman), Spider-Boy (Spider-Man and the Conner Kent Superboy), Speed Demon (Ghost Rider and The Flash), Iron Lantern (Iron Man and Green Lantern), and more.
The characters appeared in stand-alone issues of their own comics, co-published by DC and Marvel under the Amalgam Comics banner.
Per the DC Wiki, "With the help of the interdimensional hero named Access, the Living Tribunal and the Spectre managed to separate the two realities and the Amalgam Universe ceased to exist. Later, its hero Doctor Strangefate would return and attempt to revive it, and while Strangefate was defeated, it would ultimately be allowed to continue in its own pocket reality, which was given to Access for safekeeping." The character of Access, created for the crossover event and co-owned by the publishers, even had a short-lived series of his own.
Unfortunately, the identity of the Dark Claw cosplayer isn't known; Pat Loika, who shared the image, is a photographer well known within the geek community. You can check out his Instagram feed for plenty more cool coplay from this and other conventions.