A big Queen Siren! With a big powerfull scream, cut scene can be her putting the chest thing on the little screamers and breaking their arms as they try to claw at her(because the little sirens arms are all withered and useless for idk why)
She has long arms and grabs you screaming in your face, which bloods up your vision, stuns and deafens you for a bit after she let's go.
Not only does her scream destroy grenades like the little ones, but also rpg-7 fire and all other explosives, only way to take her down is sheer fire power.