I liked scamps, thought they were cute as hell. Mudcrabs were never much of a problem, other than the fact that they can disease you. Cliff racers can be annoying at low levels, but aren't that bad later on.
Honestly Dragons in this game get pretty damn annoying after awhile. Especially if all they do is dive bomb you and then fly away. And you can't FT while they are around, so you either have to try to force them to land or run far away.
Also if you don't have: SPOILERS! ! ! ! ! ! The Dragonrend? shout yet to bring them down to the ground from the MQ.