Thus question is unanswerable because it depends on how big big is to you and what type of penguin you are talking about.
This said, the extinct, Inkayacu paracasensis, or Water King, was nearly five feet tall, about twice the size of an Emperor penguin, the largest living penguin today.
About as big as a pizza slice
Emperor Penguins can weigh about 90 pounds.
as big as your mom
22cm
do pengin have big eyes
About a foot tall.
because they have big hands
About the size of a sparrow.
Helps them swim faster
big, medium & small!
because they have big hands
by making big colinies