I am looking for an English equivalent for a proverb of my language which says: "A wolf (a bad person) will never laugh at you, but it wants to get something (an achievment) from you".
I have found a similar saying in English, but I have my doubts if native speakers use it;
- Beware of greeks bearing gifts. (With reference to the story of "Trojan horse".)
Please help me to find its English Equivalent.