Collar of Language (Familiar Item) (3.5e Equipment)
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Collar of Language: This magical collar allows a Familiar or other magical creature to communicate with others. The creature it is worn by must first be a magical beast. Secondly, it must be able to speak and understand a language (such as a Familiar's native speech with its master). If either of these conditions are not met, the collar does not function.
The Familiar may activate or deactivate the collar's magic as a free action. The collar functions similarly to a Comprehend Language spell that works both ways and only translates one language (usually common). When active, the Familiar hears anything spoken in the selected language in its own arcane language, and similarly anything they say in their arcane language translates back into the collar's selected language. While the Familiar appears to be speaking perfect common (or Elvish, Dwarven, etc.), it is in fact merely an illusion that the Familiar is speaking your language. While this does not affect thinking creatures, unthinking ones, such as golems or unthinking undead, will not hear the speech translated, nor will anybody snooping around via scrying effects (at least without magical help, as normal).
CL ; Craft Wondrous Item, Comprehend Languages; Cost 1k GP, 80 XP,; Market Price: 2,000 gp