And Aaron stretched out his hand over the waters of Egypt;
and the frogs came up, and covered the land of Egypt.
and brought up frogs upon the land of Egypt.
Exodus 8:6,7
"The 2nd plague, of an immense number of frogs, attacked the
Egyptian goddess Heqet, symbol of good crops (derived from the Nile
waters) and childbirth, usually depicted as a woman with a frog’s head;
as well as Isis, another fertility goddess. 
Frogs were sacred to the
Egyptians. However, these goddesses were powerless to prevent these
symbols of life from becoming rotting piles of death.
Interestingly, the Egyptian magicians mimicked the plagues of blood and frogs with their enchantments (Exodus 7:22; 8:7).
These could have been simulations, but more likely were demonic
miracles, as miracles are evidence of supernatural power, not just of
God’s power.
God allowed the magicians to add to these two plagues, but not to reverse them!" CMI