The boss is hosting a costume contest at work, and there's a big cash prize for the winner!
Oh, those "mundane" Halloween 
costumes are popular right now.
.أزياء الهالوين "الطبيعية" تلك ذات شعبية الآن
Oh, diese banalen Halloween-Kostüme
sind gerade sehr beliebt.
Ah, ahora se llevan mucho
esos disfraces "cotidianos".
Ah, questi costumi "ordinari" 
ora sono molto popolari.
Ah, essas "fantasias mundanas"
andam bem populares ultimamente.
Такие «обычные» костюмы
на Хэллоуин сейчас популярны.