Monstrous Spider, Colossal (CR 11)

Colossal Vermin
Alignment: Always Neutral
Initiative: +2 (Dex); Senses: darkvision 60 ft., tremorsense 60 ft., and Spot +7*

AC: 22 (-8 size, +2 Dex, +18 natural), touch 4, flat-footed 20
Hit Dice: 32d8+64 (208 hp)
Fort +20, Ref +12, Will +10
Speed: 30 ft., climb 20 ft.
Space: 40 ft./30 ft.
Base Attack +24; Grapple +50
Attack: Bite +26 melee
Full Attack: Bite +26 melee
Damage: Bite 4d6+15 plus poison
Special Attacks/Actions: Poison, web
Abilities: Str 31, Dex 15, Con 14, Int -, Wis 10, Cha 2
Special Qualities: Vermin
Feats: -
Skills: Climb +16, Hide -10*, Jump +10*, and Spot +7*
Advancement: 33-60 HD (Colossal)
Climate/Terrain: Temerate forest
Organization: Solitary
Treasure: 1/10 coins, 50% goods, 50% items

Source: Monster Manual

All monstrous spiders are aggressive predators.

Monstrous spiders come in two general types; hunters and web-spinners. Hunters rove about, while web spinners usually attempt to trap prey. Hunting spiders are speedier than their web-spinning counterparts and use higher speed numbers shown in parentheses.

Monstrous spiders of both types have roughly circular bodies surrounded by outspread legs: 40 feet wide* and 10 feet high.
*The number includes the spider's body and its legs; the actual body diameter is about a third of the total.