A simple test utilizing some images under the tag anal_knotting from e621.

Recommended tags for better results: 'canine penis', 'knot', 'anatomically correct penis', and 'internal' (if you want the composition-like knotting internal view).

Currently, the model is mainly trained with canine anthro character illustrations. In case you want results similar to the human_on_anthro e621 tag, especially for male humans, I recommend including in the negative prompt some of these tags to avoid humans with canine penises and tails: human tail, human with canine penis, canine penis on human, detached penis. Other tags may deliver similar results.

As said in the discussion, I intend to improve and expand the model, including other species/characters and solving some issues.

Please be kind. This is my first model. Constructive criticism is appreciated, though.