Thor did not do this.

He fronted the danger that was coming, and reared himself up on his hind quarters.
Twenty feet away the trail he had followed swung sharply around a projecting bulge in the perpendicular wall, and with eyes that were now red and terrible Thor watched the trap he had set.
The pack was coming full tongue.

Fifty yards beyond the bulge the dogs were running shoulder to shoulder, and a moment later the first of them rushed into the arena which Thor had chosen for himself.

The bulk of the horde followed so closely that the first dogs were flung under him as they strove frantically to stop themselves in time.
With a roar Thor launched himself among them.

His great right arm swept out and inward, and it seemed to Muskwa that he had gathered a half of the pack under his huge body.