The existing 404 page is pretty lame, so sprucing it up a little doesn’t seem like such a bad idea.
Here's one I made myself. I used Bootstrap 4 so it has a more modern look to it.
[code]
<!doctype html>
<html>
<head>
<title>404 - Not Found</title>
<link href=“https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/css/bootstrap.min.css” rel=“stylesheet” integrity=“sha384-MCw98/SFnGE8fJT3GXwEOngsV7Zt27NXFoaoApmYm81iuXoPkFOJwJ8ERdknLPMO” crossorigin=“anonymous”>
<script src=“https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/js/bootstrap.min.js” integrity=“sha384-ChfqqxuZUCnJSK3+MXmPNIyE6ZbWh2IMqE241rYiqJxyMiZ6OW/JmZQ5stwEULTy” crossorigin=“anonymous”></script>
</head>
<body>
<div class=“jumbotron”>
<h1>
You look lost.
</h1>
<p>
But don’t worry. Tech support will be able to fix your problem. <em>(For a one-time-charge of only $599, of course.)</em>
</p>
</div>
<div class=“container”>
<h3>
Here’s some links to get you back on track.
</h3>
<ul>
<li><a href=“/”>Home</a></li>
<li><a href=“https://wiki.scammer.info”>Wiki home</a></li>
<li><a href=“/”>Join the Discord</a></li>
</ul>
</div>
</body>
</html>
[/code]