Zylo egg

From Memory Alpha, the free Star Trek reference.

Zylo eggs were the object of one of Data's first attempts at creativity.

In-mid 2364 Lieutenant La Forge and Lieutenant Commander Data investigated the question "Can Data be creative". In order to find that out, La Forge suggested that Data paint some Zylo eggs. It is unknown, how effective this test was, as Commander Riker was unable to recognize the subject of the painting as Zylo eggs. (TNG: "11001001")