Rule 34 Dev - 2018 4_fingers anthro ass back_muscles balls bioluminescence brown_hair brown_skin collar dragon glowing grey_background hair looking_at_viewer looking_back male male_only markings nude oddbaillie perineum presenting presenting_hindquarters rear_view scalie silvertongue simple_background smile solo spiked_tail spikes standing tank_the_dragon tendrils thick_tail|3414218080