Thus far, Itoo has "appeared" mostly on wanted posters scattered throughout areas of the East Blue. These tend to vary greatly in detail; the most detailed depicts him as a man with an untidy mop of brown hair and matching beard.
Like Pandaman, Itoo's name has independently appeared on a number of other items, most notably alcohol bottles.
Anime and Manga Differences
Due to its tendency to gloss over small background details from the manga (especially in its early episodes), the anime has kept few, if any, of Itoo's appearances. Among its many Chapter 1 adaptations, only the Episode of East Blue special maintained the angle and composition of the scene "introducing" his wanted poster in the back of Partys Bar; even this adaptation, however, redrew the poster to feature someone else.
↑One Piece Blue: Grand Data File (p. 30), Itoo's "proper" name is rendered in Roman letters glossed with katakana (presumably to differentiate from the real-life Itoo, who always renders his name in hiragana).