Swarms

Swarms are a staple of many fantasy settings. Some swarms form in nature when several animals move en masse and others are the result of magic.
When dealing with swarms, it is far easier to manage the swarm as a collected unit rather than roll for each individual creatures. Swarms inflict lethal (or occasionally bashing) on all targets within range each round and they act on the same initiative value.
To evade a swarm by Dodging it, each success removes a die of damage and your character can move normally.
If a character botches his dodge or takes three unsoaked levels of damage, the swarm has knocked them down. This limits mobility of the character to a few yards a turn and reduces the swarms difficulty to inflict damage to 5. Actions involving getting up and getting away are at +1 or +2 difficulty depending on the strength of the creatures in the swarm.
Brawl attacks, even with natural weapons, knives, arrows, and most thrusting weapons can only inflict one health level of damage on a successful attack. Large weapons like staves, axes, and slashing swords inflict their normal damage, as do area of effect attacks. A swarm reduced to zero health levels is either killed off or dispersed, probably a combination of the two.
A human can conceivably outrun a swarm of bugs or rats, but outrunning a swarm of hyenas or birds is out of the question.

Scarterran Swarms

Small Bugs 1 die of damage per turn, 5 health levels, 2 Initiative Rating
Large Bugs 2 dice of damage, 7 health levels, 3 Initiative Rating
Flying Bugs 2 dice of damage, 5 health levels, 4 Initiative Rating
Birds or Bats 4 dice of damage, 9 health levels, 3 Initiative Rating
Rats 3 dice of damage, 7 health levels, 3 Initiative Rating
Large Rats (foot long or bigger) 4 dice of damage, 9 health levels, 3 Initiative Rating
Feral Cats 3 dice of damage, 6 health levels, 6 Initiative Rating
Wild Dogs 6 dice of damage, 15 health levels, 4 Initiative Rating
Vorpal Bunnies 15 dice of damage, 50 health levels, 10 Intiative Rating

Scaraquan Swarms

Small Bugs 1 die of damage per turn, 5 health levels, 2 Initiative Rating

Large Bugs 2 dice of damage, 7 health levels, 3 Initiative Rating

Swift Bugs 2 dice of damage, 5 health levels, 4 Initiative Rating

Small Biting Fish 3 dice of damage, 7 health levels, 3 Initiative Rating

Large Biting Fish (foot long or bigger) 4 dice of damage, 9 health levels, 3 Initiative Rating

Swift Biting Fish 3 dice of damage, 6 health levels, 6 Initiative Rating

Small Sharks 6 dice of damage, 15 health levels, 4 Initiative Rating