chū shēng niú dú bù pà hǔ
lit. newborn calves do not fear tigers (idiom)
fig. the young are fearless
初
chū
at first
生
shēng
to be born
牛
niú
ox
犊
dú
calf
不
bù
no; not so
怕
pà
to be afraid
虎
hǔ
tiger