That's a clear case of "water off a duck's back".

I can't believe you're so clueless. You're like a babe in the woods.

The snake swallowed a frog.

We dissected a frog to examine its internal organs.

No sooner had I opened the box than a frog jumped out.

Like water off a duck's back.

The prince was changed into a frog.

The prince was turned by magic into a frog.

He that stays in the valley shall never get over the hill.

The boy threw a stone at the frog.

The kid drew back from the frog when it moved.

There used to be a lot of frogs in this pond.

This meadow abounds in frogs.

Frogs are afraid of snakes.

The frog inflated himself more and more, until finally he burst.

I can't distinguish a frog from a toad.

Let's return when the frog croaks.

A frog came out of the water.

Tadpoles become frogs.

I'll bewitch him into a frog!