For the book, see VISSER
A Visser is a rank in the Yeerk army equivalent to an Andalite War Prince or a human Warlord or General. There are 47 or so Vissers. They are one rank below a member of the Council of Thirteen. To obtain the rank of Visser, a Yeerk has to climb the large hierarchy, slowly going lower in number designation, then receiving the rank of Sub-Visser. Every notch up in the ranking is accounted for either by that individual's achievements or by the demotion (or elimination) of their superiors, so usually every Visser must be ruthless and brutal as well as conniving and powerful. K.A. Applegate wrote a book titled "VISSER". It portrays Edriss 562 (A.K.A. Visser One) on trial for treason by the Council of Thirteen.