Hide your daggers - Daggers Ulrik has two horns
Hold your tongue - "Ulrik is a creature of few words but grand, dark thoughts. " from profile.
Speak only lies/do only wrong - "The stallion is racist to the core and find the other species merely pawns in a much larger game. " from profile.
Nine foot box, 1 foot for every year - Ulrik is 9 years old.