Well, if they were feathered and close to modern day birds, would it not be something like a cloacal kiss? to me that makes the most immediate sense. (attached is a diagramme of it, I guess in your pic t-rexes are closest to it)

I got a HP character too, and the same one a psychiatrist I worked under used to call me after. (in 2015 though, prior to Ms Rowling heel-turning to the TERF side). Is it fair to say I feel typecast by this list? I feel like I'm just a product of that era now...