violently

at
Her horse shied violently at a gorse bush.

Shy is used with these nouns as the subject:
horse

be, feel, look, seem, sound
Please don't be shy—I won't eat you!

become, get, grow

extremely, fairly, very, etc.
desperately, excessively, painfully, terribly
As a teenager I was painfully shy.

all
She went all shy and hid behind her mother.

almost
a little, slightly, etc.
naturally
He is a naturally shy, retiring man.

chronically (esp. BrE)

around
She was terribly shy around strangers.

of
I was a little shy of them at first.

with
You don't have to be shy with me, you know.

Shy is used with these nouns:
grin, look, smile, teenager, type