Here is a WIP Suggested by Ed, Refined by Elliot Vigil, and assembled by me so far. Question is, Rhino head, or Warsphinx head? Here is the rhino head.

Hmmm... with the rhino head, the skins won't match, with the Sphinx head it won't be a rhinox. I would go with the Rhino, remove the back of the head(the shell thing), and go to greenstuff town, blending it together and giving it a more rhino skin wrinkled texture. Of course with a big brute straddling it, you may not even notice.
How does its size compare to a Ogre rider? I kinda thought the sphinx was a little smallish.

Heres some pictures with the howdah and the Arabyan Maneater on top, I think i may remove the head covering and greenstuff, looks a bit too tomb kingy.

no no no if you want that to work at ALL you need to cut the rhino head to the jaw line and then put the green mold around the neck then it will look the best you can get it. Cause its neck is too long looks weird.

the ogre looks good but id pose him closer to the front and make sure his footing is squared up. But yeah the head of the rhino needs be shortened up a bit around the neck. I do like the extra long horn on it. Id try to green stuff 2 more shorter ones and put them near that big long one though because your forge world ones have 4 horns. Also id make one look like it was broken to add a bit of flavor. But i cant wait to see it painted the thing is going to be really cool on the table!!!!

Here's some more progress, Still needs more work on adding gutplates and other ogre stuff...





I guess the biggest thing right now is the neck issue, I took off the armor plating, and that has alleviated it I think. Actually comparing what I have to the rest of the Rhino model, It seems to be pretty good scale wise, and the plastic toy i got was exactly the right size, fortunately. But still, tell me if the neck is still too long. I fixed the Howdah too, so the ogre doesn't wobble around up there, it was uneven footing. I still need to glue on more gut plates to hide the hieroglyphics. Removing them carefully doesn't seem like the ogre thing to do.

honestly i really like what u did with it mad props for reals

Nice. It is a bit long though. You might transition from the head to the body as more of a hump, instead of curving downward, that may give it more bulk to alleviate the length. Also, maybe bulk out the stomach, the back half still has a felines feel. Rhinos are almost fat, not sleek. Also, have you thought of fur? I have seen furry rhinoxs in the past, and that can look good, and hide a lot of stuff.

Yea i would do the hump, just remove the green mold and mold around the shoulders to give more bulk
Also cut off the tale at the ass and mold a little bitty tale then it will be perfect!!

Hur, funny conversion looks funny.

But really its starting to look cool. keep us updated and show us when it is fully painted.