But anyways, some nice mutation ideas
Superhuman Sight: +1 visibility range, +1 ranged attack str, +10% ranged attack limit
Massive Brain: +10 spell damage, 30% resistance to magic, -30% strength. (for mages)
Horribly Deformed: Causes fear when attacking, -1 unhappiness in nearby cities, and a penalty to diplomacy when near cities (look at pelemoc's Schemer promotion for example)
Thick Fur: +20%

in tundra and snow. +30% resistance to Cold. -25% resistance to fire
Scales: (excludes fur) +40% fire resistance
Cold Blooded: Cannot enter Snow or Tundra. +25% strength in Jungles, deserts, and Burning sands
Gills: Can walk on water, but not enter ocean. Ignores river/attack from ship penalties.
Fins: Double movement in Water
Tentacles: +25% vs Melee/Recon units, +1 first strikes.
Powerful Legs: +25% vs Mounted units, +1 movement, +20% retreat chance
Climbing Talons: Can move through impassable terrain, ignores building defences when attacking (climbs city walls)
Nimble: -20% strength, +45% vs Archery units, +20% retreat chance
Venom Sacs: +1 poison strength, Immune to poison.