The chairman for Flynn and Co., he is a stereotypical buisnessman, selfish and money hoarding. He doesn't agree with Phineas' childish ideas, and doesn't believe he has what it takes to run a business. He concocts various schemes to bring down Phineas so he can become CEO, but they always get him in trouble with Phineas. A running gag is whenever his real name is mentioned, everyone listening giggles. His trademark catchphrase is " I hate those kids!"
Arnold dislikes Phineas' ideas for the company, in fact he hates just about every idea Phineas has. He tries to bring down Phineas with his schemes, but is always foiled by Phineas and Ferb's kids (espishely Julia).
If there is one thing Arnold hates more than Phineas' ideas, its kids. He mostly hates Julia because #1: she and her siblings foil his plans, and #2: her personality reminds him of Phineas.
Mr. Biz sees Jacob and his sibblings as a threat to his plans and also likes to make bets with him (rarely).
If one of the Flynns that can scare Mr. Biz, It would be Isabella. Whenever his plots fail, she sugests to her husband (Phineas) to fire him.Fortunetely for him Phineas doesn't have the heart to do so.
Biz Hates Ferb as much as he hates his boss: Phineas Flynn (Due to the fact that His boss and Ferb are brothers.)
Biz also hates Lizzie the same as Julia. Due to the fact that they lead their sibblings to foil his plans of company domination.
Biz is very jealous with Dill. Dill was considered more important than anyone else in the company, making Biz feel kicked off. Biz always wants to bring down Dill, but in the end, they just never contacted each other anymore.