Easy enough to create, as I did: Click the "Edit" link just under the image, and in the list of tags, type "character:" and then the character's name after the colon. Kinda surprised this is the first Rodimus Prime pic (or at least the only one now labeled as such) on Danbooru, though.
Actually he would appear in two image if you count post #818553 though that's only if you considered the part where he was opening the Matrix and during that light show Rodimus and not just Hot Rod.
