foam at the mouth

The servant, who had not stayed long enough to have crossed the court to Conrad’s apartment, came running back breathless, in a frantic manner, his eyes staring, and foaming at the mouth.

My lord,

Now fear is from me, I'll speak troth. Lord Cloten,

Upon my lady’s missing, came to me

With his sword drawn; foam’d at the mouth, and swore,

If I discover’d not which way she was gone,

It was my instant death.