The 10 Plagues in Exodus are all attacks on Egyptian gods. For example, turning the Nile to blood: The Nile was a god to the Egyptians, and then turning it to blood was imagery of killing said god. Frogs were also considered gods, and when frogs were going flipping everywhere (plague 6 or something), Egyptians would be horrified to step on one of their gods. Similar to the Nile, when God cast darkness upon Egypt, it was like killing the sun (Egyptian god Ra).
So it was really big that God asked the Jews to slaughter a lamb at the first Passover. The lamb was an Egyptian god. God said “Kill this animal that Egyptians consider a god, and paint your door posts with its blood”–and everyone knew that the penalty would be death. So God was basically telling them to risk their lives to trust that He would deliver them.
Edit: Frogs were the second plague. Thanks to all who commented so I could be lazy and not Google it : )
Edit: so if I had known that this post was going to hit 10k+, I might’ve used clearer language. Some of the Plagues dealt with animals which symbolized Egyptian gods (ex. Frogs, lambs). Others attacked the powers of Egyptian gods (your god can cure boils? Well I hope he can because you all have them now). The last plague involved killing a lamb, which symbolized, I believe, an Egyptian fertility god, and also directly struck Pharoah, who was considered a god, by killing his son. Thank you all for great discussion, and the privilege of this post getting 10k+ ratings : )
This is a popular pseudo-scholarly explanation of the plagues I see repeated all the time, but it is not widely held by scholars. Rather, the plagues are seen as closely corresponding to the curses described by Assyrian vassal-treaties. They threaten disease, darkness, death of offspring, locusts, floods, death without proper burial, poisonous drinking water, fire, lice, etc. against nations who break their treaty with Assyria. Elsewhere, the Pentateuch uses vassal treaty language to express the relationship between Israel and yahweh.