A. Because they commanded the Israelites to bring them wild animals (Shemot Rabbah 11:3).

B. That also the other nations mixed with Egypt enslaved Israel, therefore they were struck with the plague of mixed wild animals (Minchat Eliyahu, Chapter 24).

C. For delaying the Israelites from coming to Jerusalem, where they were not mixed, but each craftsperson was on their own (see Zohar HaKadosh, Part 3, 78a. Yalkut Shimoni, Devarim, Remez 953).

D. For causing the Israelites to mingle with them and learn from their deeds (Kli Chemdah, Va'era).