▁He ▁is ▁the ▁ment or ▁of ▁Per cy ▁Jackson ▁and ▁the ▁activities ▁director ▁at ▁Camp ▁Half - B lo od . ▁In ▁The ▁Light ning ▁Th ief , ▁he ▁first ▁appears , ▁dis gu ised ▁as ▁a ▁Latin ▁teacher ▁at ▁Per cy ' s ▁school . ▁He ▁uses ▁an ▁en ch anted ▁wheel ch air ▁to ▁conce al ▁his ▁horse ▁half . ▁Ch ir on ▁is ▁played ▁by ▁Pier ce ▁B ros nan ▁in ▁the ▁first ▁film ▁and ▁by ▁Anthony ▁Head ▁in ▁the ▁second ▁film . ▁In ▁the ▁musical , ▁he ▁is ▁port rayed ▁by ▁Jonathan ▁Rav iv . ▁ ▁Horn ed ▁Cent a urs ▁– ▁A ▁race ▁of ▁cent a urs ▁with ▁horn s ▁stick ing ▁out ▁of ▁their ▁heads ▁and ▁their ▁horse ▁half ▁is ▁pal om ino . ▁These ▁cent a urs ▁enjoy ▁killing ▁dem ig ods . ▁In ▁The ▁Son ▁of ▁Ne pt une , ▁they ▁attacked ▁Camp ▁Jup iter ▁where ▁most ▁of ▁them ▁were ▁either ▁killed ▁or ▁have ▁retre ated . ▁ ▁Party ▁Pon ies ▁– ▁An ▁extended ▁family ▁of ▁row dy ▁cent a urs ▁who ▁res ide ▁in ▁the ▁United ▁States ▁with ▁chap ters ▁ha iling ▁from ▁each ▁respective ▁state . ▁They ▁are ▁key ▁players ▁in ▁two ▁major ▁inc idents ▁in ▁the ▁series . ▁In ▁The ▁Sea ▁of ▁Mon sters , ▁they ▁go ▁along ▁with ▁Ch ir on ▁and ▁rescue ▁Per cy ▁from ▁Luke ▁during ▁their ▁du el ▁on ▁the ▁Princess ▁And rom eda . ▁In ▁The ▁Last ▁Olymp ian , ▁they ▁help ▁Ch ir on ▁and ▁the