Green Slime (CR 3)

Medium Ooze
Alignment: Unaligned
Initiative: +9 (stealth); Senses: blindsight

AC: 20
Hit Dice: 3d10+24 (47 hp)
Fort +23, Ref +17, Will +20
Speed: 0 ft.
Space: -
Base Attack -; Grapple -
Attack: +7 vs Reflex to engulf (1d6+3 acid damage + 5 per round.)
Special Attacks/Actions: Engulf, acid, Rapid Dissolution (1d6 extra points acid damage at will)
Abilities: Str 11, Dex 16, Con 11, Int 17, Wis 3, Cha 1
Special Qualities: Immune to gaze; Resist 5 acid; Vulnerability 5 fire, 5 cold, ooze traits
Feats: -
Skills: Hide 11
Climate/Terrain: Any underground
Organization: Solitary
Treasure/Possessions: None

Source: Web

The green slime slithers up cavern walls and waits to drop on sources of heat. It devours flesh, bone, and metal with equal aplomb.

Green Slime Tactics

In battle, a green slime attacks the nearest creature and uses rapid dissolution to dissolve the creature into slime.

Engulf (standard; at-will) Acid +7 vs. Reflex; 1d6 + 3 acid damage, and the target is engulfed (save ends). While engulfed, the target takes ongoing 5 acid damage and is restrained. While a target is engulfed, attacks that target the green slime deal half damage to the slime and half damage to the engulfed creature. While it has a creature engulfed, the slime can make attacks only against the engulfed creature.

Rapid Dissolution: A green slime's attacks deal 1d6 extra acid damage to a creature that is taking ongoing acid damage.