As a standard action that provokes attacks of opportunity, a character can wind the key on this 4-foot-long serpentine clockwork enough to power it until the end of her next turn. For every additional standard action spent winding it, the rattler is powered for another round, to a maximum of 10 total rounds. The mechanism ticks softly while being wound and unwinding (Perception DC 15 to hear).
When a character removes the key (a swift action) until the rattler winds down, at the start of each of that character's turn, the rattler slithers 20 feet in a straight line, rearing up every few seconds to extend its forked tongue and make noise with its rattle (Perception DC 0 to hear). Anyone who sees it from farther than 30 feet away must succeed at a DC 10 Perception check to realize it is not an actual snake. The key-wound rattler can neither see nor hear. If it runs into an unyielding surface, it bumps around until it feels an open path, rotating first to the right and then to the left before going back the way it came. If it bumps into anything that is neither hard nor still, it attacks with its bite (+5 attack, 1d3 nonlethal damage) until the obstacle moves away. While moving, a key-wound rattler's AC is 12 and it provokes attacks of opportunity as normal. At the end of the turn in which it winds down, it curls up as if to sleep. A key-wound rattler has hardness 10 and 10 hit points. It is not a creature, and does not threaten spaces or act except as described above.
- Dungeoneer's Handbook
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