C23 H.O. Clown

This guy has some unfortunate initials, depending on how you pronounce them. Wikipedia explains the derivation: "The name HO is derived from the fact that its 1:87 scale is approximately half that of O scale which was the smallest of the series of older and larger 0, 1, 2 and 3 scales introduced by Märklin around 1900. In most English-speaking markets it is pronounced "aitch-oh" and written with the letters HO today, but in German it is pronounced "hah-null", and still written with the letter H and number 0."

Below is an image from the Clown Around catalog insert that shows H.O. Clown with a color scheme that differs quite a bit from the production version.