With html you're limited on fonts, so in order for your readers to see an ugly font you'll have to typeset the entire letter in PhotoShop and then export the entire thing as a slice and dice graphic. If you go this route you're not worrying about
SEO or slow load times.
But perhaps you mean an ugly looking website instead of an ugly looking font? In that case, if you've never read a book on basic design then the website you create will more than likely fall into the butt-ugly category without much effort on your part.