The word(s) "beware" appears 12 time(s) in 12 verse(s) in Quran in Muhammad Pickthal translation.

(11) And when thou seest them their figures please thee; and if they speak thou givest ear unto their speech. (They are) as though they were blocks of wood in striped cloaks. They deem every shout to be against them. They are the enemy, so beware of them. Allah confound them! How they are perverted!

(12) O ye who believe! Lo! among your wives and your children there are enemies for you, therefor beware of them. And if ye efface and overlook and forgive, then lo! Allah is Forgiving, Merciful.