Possible bug: monsters ignore water
Many monsters appear to have Swimming at 100
In prerelease 6, several non-flying monsters seem to ignore rivers, walking through them with no ill effects. Confirmed with a wererat and the cute dog (although the latter might be on purpose, can't remember if the cute dog could swim in earlier releases).
Of course the idea might be that they simply learned to swim, in which case I want the same swimming lessons as they had - no monster was ever perceived to suffer drowning or rusting damage.