ok guys heres the thing i have been hunting tigrex from quite sum time now for its skull shell i hunted 32(yes this is true) i did many stuffs the i heard u had to do to get his skull but nothing worked so at 29 tries i thought of trying sumthin so i did so what i did was when u first c tigrex plant a shock trap immediately and let him run to u and get trapped and keep hitting his head till it breaks (duh) but wait!!!!!!!!!!! after it brakes for the 1st time do not !!! i reapeat do not!!!! hit his head agen for sum reason it will not give the skull if u break it one more time u know like it will flinch agen. i m not sure if this is really it or im just luky cuz i did this 3 more times and i got the skull every the time i thought of this but im not sure if im the 1st one so yea im just gonna say i found about this on my ownalgee3k