He that visits the sick in hopes of a legacy, but is never so friendly in all other cases, I look upon him as being no better than a raven that watches a weak sheep only to peck out its eyes. Seneca
Foster a raven and it will peck out your eyes. Spanish Proverb
One crow does not peck out another's eyes. Dutch Proverb
Crows do not peck out crow's eyes. Portuguese Proverb