When you kill a horse and empty all of it's guts out then fill it with bombs and poo. Then you replace the hooves with wheels and push it into the middle of a priceless museum showroom.
After this, you detonate the bomb and damage everything in the room and cover the people with a mixture of horse skin and poo.
Guy 1: Noo wayy you need to come see this!
Guy 2: Come see what?
Guy 1: This total nutcase just Horsebombed a The modern art museum.
Guy 2: Modern art is a load of crap anyway.