Web (ex):
"Creatures with the web ability can use webs to support themselves and up to one additional creature of the same size. In addition, such creatures can throw a web up to eight times per day. This is similar to an attack with a net but has a maximum range of 50 feet, with a range increment of 10 feet, and is effective against targets up to one size category larger than the web spinner. An entangled creature can escape with a successful Escape Artist check or burst the web with a Strength check. Both are standard actions with a DC equal to 10 + 1/2 the creature’s HD + the creature’s Con modifier. Attempts to burst a web by those caught in it take a –4 penalty."
Net:
"Benefit: When you throw a net, you make a ranged touch attack against your target. A net's maximum range is 10 feet. If you hit, the target is entangled. An entangled creature takes a –2 penalty on attack rolls and a –4 penalty on Dexterity, can move at only half speed, and cannot charge or run. If you control the trailing rope by succeeding on an opposed Strength check while holding it, the entangled creature can move only within the limits that the rope allows. If the entangled creature attempts to cast a spell, it must make a concentration check with a DC of 15 + the spell's level or be unable to cast the spell."
Entangled:
"The character is ensnared. Being entangled impedes movement, but does not entirely prevent it unless the bonds are anchored to an immobile object or tethered by an opposing force. An entangled creature moves at half speed, cannot run or charge, and takes a –2 penalty on all attack rolls and a –4 penalty to Dexterity. An entangled character who attempts to cast a spell must make a concentration check (DC 15 + spell level) or lose the spell."
Question:
Giant Black Widow Spider webs a PC. Is the web "anchored" as in the entangle descriptor, or is it loose like a net?