March hare
noun
a hare during its breeding season in March, noted for its wild and excitable behaviour (esp in the phrase mad as a March hare)
Example sentences from the Web for march hare
The Oracle and the over-production men will totally supplant the March-hare.
Rural Rides |William CobbettHe is mad as a March-hare himself, by all accounts; but everybody likes him.
Perlycross |R. D. Blackmore