This is a very new piece, based on Ray Harryhausen's intense Allosaurus from One Million Years B.C. This is my favorite sequence from that film, featuring a really malicious dino. I also really like the beast's design, which seems to be based more on a cobra than a lizard or croc. Definitely one of my top-ten Harryhausen sequences.
Creature from the Black Lagoon (1954)
2 hours ago