Gadget:avatar.js

var img = $("<img>").attr(
  "src",
  mw.config.get("wgScriptPath") +
    "/extensions/Avatar/avatar.php?user=" +
    mw.user.id()
);
var link = $("<a>")
  .attr("href", mw.util.getUrl("Special:UploadAvatar"))
  .append(img);
if (!document.body.classList.contains("skin-vector-legacy")) {
  $("#pt-userpage-2").before($('<li id="pt-avatar"></li>').append(link));
} else {
  $("#pt-userpage").before($('<li id="pt-avatar"></li>').append(link));
}