Answer:
He stands half in and half out of the world; he is the men,
But he cannot see below Fuji
The shore the color of sky; he is the wave, he stretches
His claws against strangers.
The last excerpt is the one that best supports the conclusion that the artist intended the wave to feel threatening. The end of the stanza states that: <em>"he is the wave, he stretches/His claws against strangers."</em> By claiming that the wave has claws, the author suggests that the wave can be scary, as it can stretch its claws and capture the people, drowning them.