馒头馒头我是包子包子包子我是馒头
[mán tóu mán tóu wŏ shì bāo zi bāo zi bāo zi wŏ shì mán tóu]
Both Mantou (Steamed Bun) and Baozi (Steamed Dumpling) are popular steamed bread in China. This phrase 'Bun bun I am dumpling, dumpling dumpling dumpling I am bun' seems humorous and fun, like playing with words, often used among familiar friends, implying friendliness, intimacy and simplicity.