J.D. DanielsArnold (voice) Francesca Marie SmithHelga (voice) Justin ShenkarowHarold (voice) Jamil Walker SmithGerald (voice) Craig BartlettBrainy (voice) / Director / Escritor Dan CastellanetaGrandpa (voice) Tress MacNeilleGrandma (voice) Craig BartlettBrainy (voice) / Director / Escritor 
