Rat, Epic (3.5e Creature)
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Captain, it appears to be a rat.
This rare breed of rat can live for hundreds of years, growing more powerful with each decade.
You should probably leave it alone.
Disease (Ex): Every Epic Rat carries at least one random disease from the following table. Each time the Epic Rat hits with a attack, the target must make a save to avoid contracting the rat's disease(s). If they are already infected with a disease, they must immediately make their next save against that disease.
Power Gnaw (Ex): As a full-round attack, an Epic Rat can rapidly chew on a target, dealing greatly increased damage.
Skills: Epic Rats have a +4 racial bonus on Hide and Move Silently checks, and a +8 racial bonus on Balance, Climb, and Swim checks. An Epic Rat can always choose to take 10 on Climb checks, even if rushed or threatened. An Epic Rat uses its Dexterity modifier instead of its Strength modifier for Climb and Swim checks. An Epic Rat has a +8 racial bonus on any Swim check to perform some special action or avoid a hazard. It can always choose to take 10 on a Swim check, even if distracted or endangered. It can use the run action while swimming, provided it swims in a straight line.