This character always started each episode with, "Ferb, I know what we're going to do today." Who is he?

Brothers can be best friends, and Phineas and Ferb certainly prove this to be true. The duo often find themselves embarking on adventures in an attempt to stay busy during summer vacation while avoiding their sister, Candace, whose sole purpose is to get them in trouble.

Asked by Jennifer Sinclair · Last updated 5 years ago · 583.1K views · SOURCE