Either a man or a mouse.
More Scottish Proverbs:
Ye may not sit in Rome and strive with the Pope.
Scottish
A man is a lion in his own cause.
Scottish
A wild goose never laid a tame egg.
Scottish
A day to come seems longer than a year that's gone.
Scottish
Married folk are like rats in a trap -- fain to get others in, but fain to be out themselves.
Scottish