"It's covered all over with little squares of velvet moss.

See!" "Suppose we lower our guns by the rope, then we can swarm down easily," replied Venning, who had seen too many branches to be interested; and passing the rope round the two rifles, he lowered them to the ground, letting the rope follow.
"I believe it's moving, or else I've got fever or something." "What's moving ?" "That;" and Compton pointed down.
"By Jenkins!" muttered Venning; and the two knitted their brows as they peered down into the shadows, for the branch certainly was moving, and moving away as if it meant to part company with the trunk.

Their glances ran along the branch outwards, and then their eyes suddenly dilated, and their bodies stiffened.
So they stood like images, their hands clasping a branch, their heads thrust forward, and their eyes staring.

On the same level with their heads and about twelve feet off was the head of that moving "branch," square-nosed, wedge-shaped, with the line of the jaws running right round to the broad part under the eyes, and a black- forked tongue flickering through an opening beneath the nostrils, It was the fixed stare of the lidless eyes, and the rigid position of the grim head poised in mid air on a neck that began like the muscular wrist of an athlete, thickening to where it was anchored on a branch three feet away to the size of an athlete's leg.

And while the head, with the three feet of neck remained rigid, the body was gliding out and up, finding an anchorage in the forks of the tree on a level with the head, in readiness for the attack.
With an effort they drew their eyes away from that cold glance that held them almost paralyzed and glanced down.