let ons ▁are ▁the ▁und ead ▁troops ▁that ▁make ▁up ▁H ades ' ▁Und ead ▁Army . ▁In ▁The ▁Light ning ▁Th ief , ▁H ades ▁has ▁ske let ons ▁in ▁army ▁uniform s ▁guard ing ▁his ▁palace . ▁In ▁The ▁Battle ▁of ▁the ▁Lab yr inth , ▁N ico ▁man ages ▁to ▁employ ▁them ▁as ▁part ▁of ▁a ▁rit ual ▁that ▁will ▁enable ▁him ▁to ▁call ▁the ▁spirit ▁of ▁his ▁sister ▁to ▁speak ▁with ▁her . ▁In ▁The ▁Last ▁Olymp ian , ▁N ico ▁and ▁H ades ▁manage ▁to ▁bring ▁a ▁tro op ▁of ▁ske let ons ▁to ▁help ▁fight ▁the ▁Tit ans . ▁They ▁are ▁later ▁seen ▁construct ing ▁a ▁cabin ▁at ▁Camp ▁Half - B lo od ▁which ▁is ▁dedicated ▁to ▁H ades . ▁In ▁the ▁" H ouse ▁of ▁H ades ," ▁they ▁are ▁on ▁the ▁dem ig ods ▁side ▁and ▁help ▁them ▁in ▁the ▁H ades ' s ▁temple ▁in ▁Ep irus . ▁ ▁Sk ol op endra ▁– ▁A ▁sea ▁mon ster ▁that ▁is ▁ 2 0 0   ft . ▁long . ▁It ▁looks ▁like ▁a ▁cross ▁between ▁a ▁giant ▁sh rim p ▁and ▁a ▁co ck ro ach ▁with ▁a ▁p ink ▁ch it in ous ▁shell , ▁a ▁flat ▁c ray fish ▁tail ▁and ▁mill ip ede - type ▁legs . ▁Its ▁face ▁is ▁a ▁sl im py ▁p ink ▁like ▁an ▁enorm ous ▁cat fish ▁with ▁two ▁glass y ▁dead ▁eyes ▁and ▁a ▁gap ing ▁to oth less ▁ma w . ▁It ▁has