Lann and Belengar were both dumbfounded by the candidate Geralt recommended.
A Shapeshifter...
The wonder of this ancient creature lies in its extraordinary ability to imitate.
As long as a Shapeshifter observes someone for a period of time, it can become that person—not just the body, but even clothes and the tools they carry can be mimicked, though of course the target's weight can't differ too much from its own.
A Shapeshifter can also copy that person's voice, way of thinking, style of behavior, professional knowledge and skills, and so on. This is because—put in Geralt's words—it can copy the victim's brain patterns and mind, or in other words... soul.
Of course, on the question of souls, Lann, who'd just come back from the World of Fire, had a different opinion.
And the reputation of Shapeshifters among intelligent species is, despite their kind nature, hardly better than that of Water Ghosts or Ghouls.
