67555
His maternal grandparents were Germanicus and Agrippina the Elder ; his mother , Caligula 's sister .
 Germanicus, Agrippina the Elder, Caligula
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Germanicus, Agrippina the Elder, Caligula