▁children ▁of ▁E ch id na ▁and ▁Ty phon . ▁It ▁has ▁a ▁hard ▁skin ▁in ▁which ▁no ▁weapon ▁can ▁pen et rate . ▁Luke ▁and ▁Atlas ▁sent ▁the ▁N eme an ▁Lion ▁to ▁the ▁National ▁Air ▁and ▁Space ▁Museum ▁to ▁stop ▁the ▁group ▁of ▁quest ing ▁Hun ters ▁and ▁Dem ig ods . ▁It ▁batt led ▁with ▁Per cy ▁Jackson , ▁but ▁was ▁hard ▁to ▁defeat ▁because ▁of ▁its ▁bullet proof ▁and ▁sword - proof ▁p elt . ▁Per cy ▁eventually ▁defeated ▁it ▁by ▁throwing ▁astr onaut ▁food ▁into ▁its ▁mouth ▁thus ▁expos ing ▁its ▁one ▁un protected ▁surface , ▁its ▁mouth . ▁ ▁N os oi ▁– ▁The ▁spirits ▁of ▁ill ness , ▁pl ague , ▁and ▁disease ▁that ▁were ▁originally ▁locked ▁up ▁in ▁P and ora ' s ▁Box . ▁In ▁The ▁H idden ▁Oracle , ▁a ▁bunch ▁of ▁N os oi ▁attack ▁Apol lo ▁and ▁Meg ▁McC aff rey ▁until ▁they ▁are ▁f ended ▁off ▁by ▁them ▁and ▁the ▁Kar po i ▁Pe aches . ▁ ▁O phi ota urus ▁– ▁A ▁half - cow / half - s nake ▁mon ster . ▁It ▁was ▁nick named ▁B ess ie ▁by ▁Per cy ▁Jackson ▁who ▁initially ▁assumed ▁it ▁was ▁female , ▁although ▁Gro ver ▁later ▁informed ▁him ▁that ▁it ▁was ▁a ▁male . ▁Per cy ▁saved ▁it ▁from ▁a ▁tra w ler ' s ▁net ▁after ▁being ▁fetch ed ▁by ▁the ▁Hi pp oc amp i . ▁B ess ie ▁was ▁supposed ly ▁the ▁creature ▁that ▁Ar tem is