evil.js

let viewport = document.body.getBoundingClientRect()
let maxWidth = viewport.width
let maxHeight = viewport.height

let outer = document.createElement('div')
outer.style = "position: absolute; top: 0; left: 0; right: 0;"

for (let i = 0; i <= 40; i++) {
  outer.append(makeImg())
}
document.body.append(outer)

function makeImg() {
  let el = document.createElement('img')
  el.src = 'https://www.peppapig.com/wp-content/uploads/sites/3/2019/02/peppa_pig_splat.png'

  let width = getRandomInt(100, 300)
  let left = getRandomInt(0, maxWidth)
  let top = getRandomInt(0, maxHeight)

  el.style = `position: absolute; width: ${width}px; left: ${left}px; top: ${top}px;`
  return el
}

function getRandomInt(min, max) {
    return Math.floor(Math.random() * (max - min + 1)) + min;
}