A Calm Lakitu is an enemy found on Vibe Island in Super Princess Peach.
Like most "Calm" enemies, Calm Lakitu is usually found asleep. If Princess Peach were to walk too quickly, she would wake it up, and it will attack like a regular Lakitu.
According to the game's Glossary, it "Sleeps calmly. Walk softly so as not to wake him."