He is described as a "slight elf with Atlantean gills", capable of inhaling through his neck and exhaling through his mouth. It appears that when he cannot suck in air fast enough, he begins wheezing.
His final appearance is in The Atlantis Complex, where he was a guard of Turnball Root. Turnball burned a thrall rune onto Vishby's neck, and made him an unknowing accomplice in his plans. Near the middle of the book Turnball betrays Vishby by electrocuting him with a buzz baton in the gut. He is later killed by the atlantean shuttle that was destroyed by one of Foaly's space probes, after rescueing Turnball and his accomplices.