Warning: This is 3.0 Edition material. It is possible that there is more recent 3.5 Edition version.

Stalking Spell

(Savage Species)

Illusion (Glamer)
Level: Sorcerer 8, Wizard 8,
Duration: 1 hour/level (D)
Saving Throw: Will negates (harmless)

As improved invisibility, except as noted above and that the creature is hidden from hearing and scent as well.
The subject radiates silence to a radius of 5 feet and neither leaves a scent nor can be detected by the scent ability.