Maybe some interesting stuff for Tzarakk some day, but for the moment here is a list of the trophy bonuses:

+---------------------------=( Trophies of Hair )=-----------------------------+
| alligator skin            train/study negate offhand penalty: +5%            |
| bear skin                 train/study mangle: +10%                           |
| bear tooth                train/study bestial frenzy: +10%                   |
| bird feathers             train/study find weakness: +5%                     |
| buffalo hide              train/study impale: +5%                            |
| bull horns                train/study alertness: +7%                         |
| chimera's tail            train/study parry: +6%                             |
| claw of the sabretooth    train/study parry: +4%                             |
| enormous fishbone         train/study hunting: +10%                          |
| hardened mud              train/study stunned maneuvers: +10%                |
| head of feline            train/study stunned maneuvers: +10%                |
| head of the sloth         train/study camping: +5%                           |
| hide of a giraffe         train/study alertness: +5%                         |
| hide of a zebra           train/study alertness: +4%                         |
| hide of the feline        train/study discipline: +6%                        |
| hyena's head              train/study impale: +5%                            |
| leopard hide              train/study mangle: +10%                           |
| mane of the lion          train/study riposte: +10%                          |
| monkey skull              train/study stun: +6%                              |
| moose horns               train/study alertness: +6%                         |
| raccoon fur               train/study bestial frenzy: +10%                   |
| reindeer horns            train/study hunting: +10%                          |
| rhinoceros horn           train/study tumbling attack: +5%                   |
| scales of a drake         train/study find weakness: +5%                     |
| scales of a seamonster    train/study discipline: +7%                        |
| shark tooth               train/study discipline: +4%                        |
| snake scales              train/study shield bash: +10%                      |
| stinger of scorpion       train/study alertness: +8%                         |
| tail of a seamonster      train/study riposte: +10%                          |
| tail of a skunk           train/study negate offhand penalty: +3%            |
| tentacle of squid         allows saddle on mount			       |
| tiger hide                train/study negate offhand penalty: +7%            |
| tooth of the sabretooth   train/study mastery of mounted combat: +5%         |
| tortoise shell            train/study bestial frenzy: +10%                   |
| tusk of the elephant      train/study combat riding: +5%                     |
| unicorn horn              train/study stun: +4%                              |
| whale oil                 train/study riposte: +10%                          |
| wings of a griffon        train/study rampage: +5%                           |
| wolf hide                 train/study discipline: +3%                        |
+------------------------------------------------------------------------------+