Normally they get as big as your hand.
around as small as mice!
A treefrog with gray eyes.
gray tree frog
Tree frogs make up the family Hylidae. The gray tree frog is classified as Hyla versicolor, the Pacific tree frog as Hyla regilla, and the giant tree frog as Litoria infrafrenata.
They will all eat spiders.
tree bugs
His name is Carl.
Some do. The gray tree frog is the only one that I know of.
Depends on what species you are asking about and where you live. There is the Austrailian green tree frog, American green tree frog, American gray tree frog. Anytime it is warm out is when you can find them. Usually mating between April and August.
a grey bellied tree frog
The grey tree frog, while not normally dangerous, can produce toxins when stressed.
It is just natural behavior, but it could also be resting.
as big as a gulf ball