The chapter titles (The Noose Tightens, Mouse Holes, Mouse Trap) represent this feeling.
What is claustrophobia?
The country Vladek wanted to flee to during the war.
What is Hungary?
In order to show Anja can't "pass" as non-Jewish, Spiegelman draws her with this, which Vladek doesn't have.
What is a tail?
Artie confesses to Mala he is concerned he is portraying his father as this.
What is a cruel Jewish stereotype?
This is the Polish nanny who worked for the Spiegelmans but refused to hide them once the war began.
Who is Janina?
The name of the most notorious concentration camp.
What is Auschwitz?
In order to show that dividing people into groups is arbitrary and foolish, Spiegelman draws mice with masks that show this.
What is a string?
Artie spends a lot of time trying to find these, which belonged to his mother.
What are her diaries?