Word usually written using kana alone

frog

かわず／カワズ only

kajika frog (Buergeria buergeri)

toad (esp. the Japanese toad, Bufo japonicus)

person who is ignorant of the real world; frog in a well

Proverb

like father, like son; the apple doesn't fall far from the tree; the child of a frog is a frog

tree frog (esp. the Japanese tree frog, Hyla japonica)

green (tree) frog

frog spawn; frogspawn

wrinkled frog (Rana rugosa)

poison dart frog (Dendrobatidae spp.); dart-poison frog

bullfrog