noun
green frog; tree frog
Refers to various green-colored frogs, often tree frogs (family Rhacophoridae) or true frogs (family Ranidae) that are green. In everyday use, it typically means a small green frog found in gardens and rice paddies.
庭で青蛙を見つけた。
I found a green frog in the garden.
青蛙が田んぼで鳴いている。
Green frogs are croaking in the rice paddy.
雨蛙 specifically refers to tree frogs (family Hylidae), while 青蛙 is a broader term for green frogs, which may include tree frogs but is not limited to them.
殿様蛙 is the black-spotted pond frog (Pelophylax nigromaculatus), which is larger and typically brownish with dark spots, unlike the smaller, green 青蛙.
Compound of 青 (あお, 'blue/green') and 蛙 (かえる, 'frog'). The reading あおがえる follows standard rendaku voicing of the second element.