This room has really
great bones, the interesting architecture should stand out! I would recommend doing a dark accent color
on the rear wall (perhaps charcoal), and painting the animal heads to
coordinate with the stone (off white), or if you’re feeling bold paint them a
bright color. A large scale plant or décor
peice by the far window (to the right of the TV) might help the room feel more
balanced.

Beautiful space...including the baby toys (they won't be there long)! This wall is not built symmetrically so accessorizing it needs to be balanced not symmetrical. I like Rochelle Lynne's idea of a darker, more saturated color on the fireplace wall and even painting the heads for more contrast and fun. Perhaps off white on 2 and black on biggest (should be high gloss). Also try a different configuration, two smaller ones stacked and the larger one centered... stairstep them with the larger one between the small ones.

Thanks for the great suggestions. Seems like you guys are ok with the animal heads themselves, just doing more with them and the wall they are on in terms of paint color. Can you elaborate on high gloss recommendation...is that to make them "pop" more? I always seem to shy away from shiny paint, but perhaps its needed here.

Frankly, I wouldn't go dark. The room needs more light. I would brighten the wall coloring and add a larger area rug in a brighter color. You also have a lot of metal accents that currently make the room appear cold. Add some wood and fabric accents. Also, is there another wall for the TV, it competes with the dramatic fireplace and makes the wall look even more busy. I would put a piece of art work on the wall where the TV is, that will add more interest and light into the room.