The vector clipart library Puzzles contains 15 puzzle symbols.
"A puzzle is a problem or game that tests the ingenuity of the solver. In a basic puzzle, one is intended to put together pieces in a logical way in order to come up with the desired solution. Puzzles are often contrived as a form of entertainment, but they can also stem from serious mathematical or logistical problems — in such cases, their successful resolution can be a significant contribution to mathematical research. Solutions to puzzles may require recognizing patterns and creating a particular order. People with a high inductive reasoning aptitude may be better at solving these puzzles than others. Puzzles based on the process of inquiry and discovery to complete may be solved faster by those with good deduction skills." [Puzzle. Wikipedia]
The example "Design elements - Puzzles" is included in the Artwork solution from the Illustration area of ConceptDraw Solution Park.