Pleasing his father, Inventions, Winning, Getting away with stuff, etc.
Losing, His machines being destroyed, Plans being derailed, etc.
Bowser Jr. is Bowser's winning cool son. He is the secondary antagonist (and sometimes as the main antagonist) of the Mario games. He first appeared in Super Mario Sunshine as the main antagonist where he graffitis Delfino Island disguised as Shadow Mario in hopes of getting him arrested, he succeeded for a little while but Mario managed to stop him. Bowser Jr. has also appeared in other games such as New Super Mario Bros., Super Mario Galaxy 2, and many more. Bowser Jr. also appears in a few spin-offs like Mario Kart, Mario Tennis. He is the only character who Bowser (his actual father) shows emotions for. Bowser Jr. is Bowser's only official son as the Koopalings have been confirmed by Shigeru Miyamoto to not be his children and just his minions. Bowser Jr. makes frequent appearances nowadays too.