I love warhead, crytek added so many easter eggs. I have screenshots of the first frog, and then the two frozen frogs, and an extra little funny thing I found on peak in crysis wars.
First is the sea mine under the floorboards on peak:
Then the frogs:
There is one more frog that I know of, and the squirell from ice age, but I have yet to find them myself.
I don't know if this is an easter egg, but I found it funny that there were Alaskan boats in Korea: