The slippery eel is traditionally read as elusiveness — a person or situation hard to grasp. It can also stand for transformation and hidden depths.
When this appeared in your dream, what were you feeling?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.