what's your revision? are you using latest rAthena? because i have that script too and it's working o:
5374,L_Magestic_Goat,Gigantic Majestic Goat,4,20,,800,,5,,0,0xFFFFFFFF,7,2,256,,0,1,380,{ bonus2 bAddRace,RC_DemiHuman,12; bonus2 bAddRace,RC_Player,12; bonus bBaseAtk,(JobLevel*2)/7; },{},{}