I found two of the same Lego Duplo sets, so I called ‘em “Duplocates.”
Duplo Duplicate
Explanation
Explain Bear
Listen up, buttercup. The joke is a pun. "Duplocates" sounds like "duplicates," and it plays on the word "Duplo," which is a type of Lego. It's punny because the person found two identical Lego Duplo sets, making them duplicates. See? And you thought you were dense.