The roars the Creature makes border on Hell Is That Noise. Seriously, the thing sounds downright demonic.
Speaking of Hell Is That Noise, the music that plays every time the Creature makes an appearance is incredibly effective. Whereas other musical cues used around the time of this movie sound dated and cheesy, the Creature's Leitmotif will make your heart leap into your throat every time it is used.
The scene where the Creature attacks Luís and Tomás is one of the most frightening sequences in the entire Universal canon. The scene starts with the Creature's hand reaching out of the water and grabbing onto solid ground, while its face is just barely visible below. Following this, we get a POV shot as the Creature lumbers toward the duo's tent. The music starts with the Creature's already-mentioned leitmotif, before morphing into a more subdued yet still ominous piece that gradually grows more and more intense. Luís looks up just in time to see the Creature entering the tent (all we are shown is its hand) and tries to defend himself by throwing a lamp at it. It proves to be in vain when the Creature grabs him, its hand covering his entire face, and throws him like a ragdoll whilst roaring like a beast from the pits of Hell. He then goes for Tomás, and the scene cuts to the exterior of the tent as he screams in either agony or terror, before slowly fading out.
Mark's death. The Gill-man tears out the hose for his oxygen tank and essentially drowns him before David can save him.
The opening scene is this as well. After a fairly boring lecture on the creation of the Earth and the nature of evolution, the camera pans down into the Amazon jungle, where a great deal of commotion is going on among a research party. The scene is done in the form of a Oner, as Dr. Maia goes sprinting out of a tent and toward the center of the hubbub. We are then treated to a an extremely jarring closeup of a fossilized claw sticking out of the side of a cliff. The way the shot is constructed, it is difficult for the viewer to know what they are looking at until the claw is right in their face. One can only imagine what that scene would be like in 3-D.
