The term you're likely thinking of is "Darwin's Fish" or "Darwin Fish".
This is a symbol used by some atheists and secular humanists. It's a stylized fish symbol, like the Christian ichthys symbol, but with the addition of a small circle in the middle to represent the eye of evolution.
Here's what the Darwin Fish symbolizes:
* Evolution: The circle representing the eye symbolizes evolution, particularly the idea of natural selection.
* Atheism or Secular Humanism: While not exclusively associated with atheism, it is a popular symbol among atheists and secular humanists.
* Counter-cultural statement: It can be seen as a playful and non-confrontational way to express non-religious beliefs.
The symbol has been used in various ways, including:
* Stickers: Placed on car bumpers, laptops, etc.
* T-shirts: With various designs incorporating the symbol.
* Other merchandise: Like mugs, keychains, and jewelry.
While not universally recognized, the Darwin Fish symbol has become a recognizable symbol for some within the atheist and secular humanist communities.