Film: Night of the Blood Beast (1958)
Height/Weight: Slightly taller than an average human.
Affiliation: Unknown, leaning on evil
Summary: If you're going to get someone pregnant in order to save your dying species, make sure you do it with consent. Otherwise, you end up like the Blood Beast. Though, to his credit, he ended up with a bunch of idiots who preferred bang bang over talk talk.
History: The Blood Beast hijacked a space ship carrying a man named John Corcoran, causing said ship to crash into the Earth. The alien's goal was to impregnate the human race with his offspring in order to save the race from itself by getting rid of it. However, the beast made sure that John not be harmed, for the human was now the host of the beast's new kids. Apparently, the alien had completely dropped the ball at some point in biology studies and assumed both man and woman could reproduce. Either way, John seemed oddly okay with his predicament, and urged the others to trust the beast. It fell on deaf ears for a number of reasons.
Notable Kills: He beheads a scientist to eat his brain.
Final Fate: After the Blood Beast's pitch fails to impress the humans, they throw explosives and kill him. However, before dying, the beast warns the humans that there are many others of his kind that will finish what he started.
Powers/Abilities: Aside from a really tough hide, the Blood Beast can eat his victim's brains and absorb their knowledge and even their whole native language.
Weakness: The heavy artillery will do the job nicely. Fire is also a good way to end it.
Scariness Factor: 3-The Blood Beast's appearance is nothing short of imposing, but his motives are unclear (albeit well intended based on his words), and he's fairly easy to kill. So that invasion might not exactly get off the ground unless they have good technology.
Trivia: -Men cannot birth kids. At all. Don't make us explain this.
-The Blood Beast suit was used in a film two weeks earlier in the production of "Teenage Caveman".