Say what you will about the movie itself, but the werewolf effects are awesomely frightening. They took the basic concept behind the Wolf Man's design from the original movie, and they made it genuinely look like a vicious, feral beast.
The opening scene, in which Ben Talbot is hunted and killed by a werewolf. Special mention goes to the shot of its claws as the beast watches him run futilely into the church.
The scene becomes even more disturbing when you learn that the werewolf is actually his father.
And later we see his body. He was completely mauled, with massive claw marks, bites and partially eaten.
The scene where an institutionalized Lawrence Talbot transforms in front of a crowd and goes on a killing spree. The part where he impales the professor on a gate is particularly gruesome.
The Wolfman chases Gwen through the dark forest tracking her scent like a hound straight from hell. Eventually Gwen is cornered between the waterfall and the hungry beast that clearly wants to eat her flesh and violently rip her apart. This then goes to heartwarming as The Wolfman appears to briefly recognize her and stops her killing intent. He then goes to Tear Jerker when Gwen puts him out of his misery.
The alternate endings:
One has Gwen get to Lawrence through the Wolfman, but when the hunters come, this time, he bites her. Gwen is able to shoot him before he can rip out her throat, but now there are two werewolves on the loose: Aberline, the Wolfman of Scotland Yard, and Gwen, the She-Wolf of London...
The other is almost the same, but this time, when he rips into her body, she's unable to act. In a twisted parallel to Sir John killing Lawrence's mother, the Wolfman kills Gwen by ripping out her throat before snarling at the camera.
The novelization is more chilling in its descriptions of scenes like the werewolf's initial attack, the transformation, and it perfectly describes the terrible power and strength of werewolves. Unlike the movie, where the Wolfman would only attack those who tried to attack him, in the novel, he's depicted as a hungry monster with almost no restraints, attacking anyone in his path, and also unlike in the movie, he actually eats his human prey graphically. Not only that, but the ways in which he kills are incredibly brutal. At one point he turns a hunter into a red mist of blood and flesh in a matter of seconds, and in the London rampage he smashes two guys with such force that their pores burst.
The Wolfman regenerates extremely fast from injuries that are not caused by silver. He is a nigh-unstoppable force of nature and a Super-Persistent Predator, and it is absolutely terrifying that most of his victims are nigh-defenseless against him. He can't be outrun, is much stronger than most of his victims, and can easily sniff out prey or hear their heartbeats or breath.
Ben's death is extremely gruesome. The werewolf slashes his belly, and his guts start to slip out of the wound. Ben feels them, but tries to not think about it, even as his legs are getting heavy. After that, the werewolf rips him apart.
The transformations' descriptions are incredibly painful to read. At a point in the mausoleum, Lawrence scream/howls so strong from the pain, that it causes insects to explode and even cracks the floor.
Sir John is even worse in the novel, as he clearly enjoys both the power he has and the raw feeling of bloodshed. In the gypsy camp attack, he actually devours men, women and children, and makes an expression of ecstasy as a woman's blood splatters on his face. When he bites Lawrence, he actually rips off a piece of flesh and eats it. During the final battle, he says that he would be the alpha and basically conquer the world and kill people in all the countries of the world with Lawrence as "his pup". Not only that, but he also had plans to turn Gwen into a werewolf and make her his mate, even calling her "his bitch".
In contrast with the movie, in the novel Gwen watches the battle between the two werewolves.
In the novelization, as much as he deserves it, Sir John's death was terrifying. He's burning alive with macabre descriptions, and his lips seem to smile as they contract from the heat. After that, Lawrence's mind sees that he finally killed the monster that killed his mother and he is happy. After Sir John's death, Lawrence's werewolf form with the flames behind him is said to look like an infernal beast.
The Wolfman's physical descriptions and the things he does. He's an 8 feet tall humanoid monster, with powerful claws and jaws (even if the victim survives the bite, a werewolf's bite can easily rip off that chunk of flesh) and extremely powerful muscles that are implied to have hellish origins. The werewolves' strength is such that a casual tackle between two of them can destroy all the windows, metals, floor and wood from just the impact, and humans have zero resistance to their attacks.
