Tip 1. Look for secret areas.
Tip 2. Every time a mudokon die, load the game to right before, or kill you're self.
Tip 3. If you find a secret area, and it seems impossible... Stay at it untill you beat it...
Sometimes the Mudokons are hidden in the shadows. If you see a shadow that looks odd (sorry, puns... I mean "looks large enough to hide a Mudokon and obviously not just for cool visual effects"). Say "Hello" and see if a Mudokon responds (be sure no Sligs or Slogs are around).