Two themes, or motifs, develop the qualities of Grenouille that evoke admiration and fascination. A metaphorical comparison suggests his resemblance to an insect, namely the tick, which perches alone in the tree until the appropriate moment to fall upon its victim beneath. Qualities shared by Grenouille and the tick are unobtrusiveness, persistence, toughness, and resistance. Encapsulated within himself, Grenouille, like the insect, gives nothing to the world and endures hard days awaiting a change for the better. The motif is particularly prominent and appropriate during the period of the young man's brutal apprenticeship to the tanner; the stupor of the work renders him numb and yet enables him to preserve himself inviolate; in the first hours gained free for himself he reawakens to the odors of Paris. Ultimately gaining insight into the metaphor as it applies to him, Grenouille realizes why he has clung so tenaciously and savagely to life: fate has picked him to be the greatest perfumer of all time. Contributing less to the admiration of the reader for Grenouille is an additional aspect of the tick metaphor in the parasitic nature of the man's relationship to other characters, whom he uses as hosts to be sucked dry.
The sensual appeal of this character and his unbridled egocentricity evoke a fascination with evil associated with the devil. Described as an abomination from the day of birth, the infant is identified with the devil by his wet nurse, not because he stinks of sulphur but because he has no odor; moreover, he walks with a limp. Since Grenouille needs nothing for his soul — not security, attention, tenderness, or love — the suggestion is that he may have none. He is predisposed towards darkness and night, at which time he becomes active. His extraordinary olfactory powers gain him the reputation of possessing second sight, a power which in the popular mind is associated with misfortune and death. The unexplained murders of twenty-five women are recognized as the work of the devil.