Worthwhile summons (early to mid)

[AdmiralZhao]

Behemoths and the skeleton calvary are both decent choices. If you have national death mages, you can convert your entire stock of death gems into summons in a single turn, which can be a nice surprise in a mid-game war. They also don't need to eat, which is a plus if you want to make a really big army to march on your opponent's capital.