This is Sophie, Killer of Socks.
She has just bravely killed not one, not two, but four pairs of socks. Not only did she kill them, but she dragged them out of the basket, from the nightstand to the bed, down to the floor, then down the hall to the top of the stairs, where she did the low "mroouw?" that says "I've killed something, come and see!!!1"
Note that she did this, and was praised four times, and given snacky treats two of those times. Three of the killed prey were displayed and mrouw'd over at the top of the stairs... the fourth one was dragged all the way down the stairs too!! I think she would have kept right on going, only four was the limit of the socks in the nest laundry basket at the time.*
At this time we are not sure why Sophie got the urge to be a brave killer. She is 17, has some minor mobility issues and can't jump up on the bed, so we have a little step-stool that she climbs to get to the bed in three steps. The only thing we can figure is that there was a notable lack of food in the bowl at one location (to wit: downstairs, but not in the bowl she walked by at least 4 times to get to the bed :) and that she figured it was her turn (comma damnit) to hunt and provide for the family.
* (Somehow at least three of the killed socks made it back to the laundry basket on the nightstand the next day, and two of these needed killing. Again. Their freshly-killed-again corpses were found on the stairs in various states of brought-down.)