New 18+ Scarlett Johansson Avengers Costume. And scarlett looks ultra fit in the suit—dishing earlier this year that she had to switch to an plant based diet to get into the unforgiving costume!! Johansson, who stars as the black widow in the avengers, initially had an issue with the durability of the costume since it kept ripping. Scarlett johansson smouldered today in a black catsuit on the set of the avengers in new york city.