Rug of Welcome

This finely crafted rug looks like a normal floor covering, 5 feet wide and 10 feet long. When commanded to guard an area, it animates and attempts to grab, then grapple any large or smaller creature that steps on it. The owner can set a password to allow creatures to pass without causing the rug to attack, and can command the rug from up to 30 feet away (though the owner need not be present for the rug to attack). The rug can attack one creature at a time; unless it is destroyed, it continues to attempt to grapple or hold its target until commanded to release.
Moderate transmutation, moderate evocation; CL 11th; Craft Wondrous Item, animate objects, Bigby's grasping hand; Price 30,000 gp; Weight 15 lb.

Animated Rug of Welcome CR 5; large construct; HD 13d10; hp 71; Init +0; Spd 0 ft.; AC 20, touch 9, flat-footed 20; Base Atk +9; Grp +23; Atk +22 melee touch (no damage, grab); Full Atk +22 melee touch (no damage, grab); Space/Reach 10 ft./5 ft.; SA improved grab; SQ construct traits; Al N; SV Fort +4, Ref +4, Will +4; Str 31, Dex 10, Con-, Int-, Wis 11, Cha 1
Improved Grab (Ex): To use this ability, a rug of welcome must hit a creature of its size category or smaller with its grab attack. (The rug has a +4 racial bonus on its grab attacks, already figured into the statistics above.) It can then attempt to start a grapple as a free action without provoking attacks of opportunity. If it wins the grapple check, it establishes a hold.

Source: Complete Arcane