Wally is a famous, living, conscious puppet.
Max is his favorite human bodyguard,and Ellie is his personal human assistant.
Wally hates most humans,except for children and Max and Ellie,who are his only human friends.
He does not yell at them or be rude to them,unlike his dealings with the rest of the human employees.
Max saved Wally from the thieves, then they became friends.
As for Ellie, she once saved him from two human men who trrture him with a knife, then they became friends.