What Does Dreaming of a Slug Mean?
Traditional Interpretation
In the tradition of Ibn Sirin and al-Nabulsi, slow-moving, slimy, shell-less creatures can point to a small trouble that secretly disturbs a person, to gossip, or to a distress growing little by little. This creature crawling on you may be interpreted as someone around you slyly trying to wear you down, while cleaning it off and removing it can signify being freed of that affliction and finding lightness of heart.
Psychological View
In modern psychology, a slimy, sticky creature can be the outward expression of suppressed disgust, shame, or a small anxiety long ignored. Your revulsion at it in the dream can indicate that a matter you now "want to take in hand" but hesitate to touch is slowly surfacing in your unconscious.
By Context
For a Single Person
For a single person, seeing a slug can point to a hesitation slowly gnawing at their heart, or to unfounded gossip from their close circle. Cleaning it away may be interpreted as shaking off confusion and reaching a clear decision.
For a Married Person
For a married person, this dream can herald small resentments accumulating over time in home life, or a minor matter waiting to be resolved. Removing the slug can indicate restoring peace through patient conversation.
Crawling on Your Body
A slug moving across your skin can point to the presence of someone in your surroundings quietly wearing you down, a relationship or environment slowly draining your energy. It may be reminding you to protect yourself by setting boundaries.
Killing / Cleaning It Away, According to Ibn Sirin
Crushing this creature, killing it, or cleaning its slime away may, in the traditional reading, be interpreted as the end of a small, long-running trouble, distress departing and giving way to ease.