Base creature values. Events, world settings, difficulty and loot bonuses can change an encounter.

Thalas
Bosstiary · BaneCreature resistance values; world limits may adjust them. Negative values indicate a weakness.
Invisibility
Base chance per roll, not a guaranteed reward. Bonuses, world multipliers and boss participation change the result. Charged items use their own quantities. Container contents also require the container to drop.
cobrafang dagger · 1 · 100%
gold coin · 1–80 · 50%
gold coin · 1–80 · 50%
small emerald · 1–3 · 7%
time ring · 1 · 7%
venom dagger · 1 · 7%
stealth ring · 1 · 1.5%
great health tonic · 1 · 1.5%
green gem · 1 · 0.5%
serpent sword · 1 · 0.5%
tidal sabre · 1 · 0.2%