From Monster Manual Expanded (1).
Monstrous Tarantula
Huge beast, unaligned
Armor Class 14 (natural armor)
Hit Points 138 (12d12 + 60)
Speed 30 ft., burrow 5 ft., climb 30 ft.
STR DEX CON INT WIS CHA
22 (+6) 12 (+1) 20 (+5) 2 (-4) 11 (+0) 4 (-3)
Skills Stealth +6
Senses blindsight 10 ft., darkvision 30 ft., tremorsense 60 ft. passive Perception 10
Challenge 7 (2,900 XP)
Multiattack. The tarantula makes two attacks: one with its forelegs
and one with its bite.
Bite. Melee Weapon Attack: +6 to hit, reach 5 ft., one creature.
Hit: 19 (3d8 + 6) piercing damage, and the target must make a
DC 16 Constitution saving throw, taking 18 (4d8) poison damage
on a failed save, or half as much damage on a successful one.
If the poison damage reduces the target to 0 hit points, the
target is stable but poisoned for 1 hour, even after regaining hit
point – Requested by vgonzalezedd@gmail.com (Alias: )