This was a simple substitution cipher. A bit of common sense would show that the first 3 words were: 'THE FLAG IS'. From there you could simply break the cipher using pen and paper (which is what I did) by using a frequency analysis, common sense, and a tidbit of logic. Looking at H, and I we see that there is a logic for subsequent characters: the prints are turned counter-clockwise one at the time in order to yield all combinations (16). Moreover, A being a single paw, it wasn't a leap to assume that the first 4 letters of the alphabet were single paws, again turned counter-clockwise for A-C.

Combining all these revealed the flag in a crisp 10 minutes with no use of a pc!
IF_ONLY_JURASSIC_PARK_WAS_LIKE_THIS