Arachnid attack
In this corner: The Alien Queen from “Aliens” (1986)
In that corner: Shelob the spider from “Lord of the Rings: Return of the King” (2003)
And the winner is: Tough call. That acidic Alien blood is a distinct advantage, and would give Shelob only one chance to get a hit in with that nasty stinger of hers. But as J.R.R. Tolkien describes her in his books, Shelob is very old, very strong and very cunning. And if the fight is on Shelob’s home turf, the Alien Queen is toast. (Next, Shelob will go eat Aragog, the giant spider of “Harry Potter and the Chamber of Secrets.”)

Hunting Season is Open
In this corner: The Predator from “Predator” (1987)
In that corner: The T-1000 Terminator from “Terminator 2: Judgment Day” (1991)
And the winner is: Two relentless hunters face off against each other, both spoiling for a victory after their humiliating losses to Arnold Schwarzenegger. The Predator’s invisibility trick will be useless on a machine that has no trouble seeing in infrared. And the T-1000’s shapeshifting abilities make it nearly impossible to kill, and completely invulnerable to the blades the Predator keeps in its arsenal. On the other hand, the only two things that seemed to slow down or stop the Terminator were extreme cold (like a tankful of liquid nitrogen) or extreme heat (like a vat of molten iron) — and the Predator has access to laser weapons that might be able to melt his liquid adversary in a way he won’t be able to bounce back from. Still, on balance I give this one to the Terminator.

Brawl of the big bacteria
In this corner: The Thing (1981)
In that corner: The Blob (1958)
In that other corner: The Creeping Terror (1964)
And the winner is: It’s sure not the Creeping Terror, a monster from one of those deliriously bad movies that “Mystery Science Theater 3000” loved to mock — supposedly a giant bacteria, it’s really just a carpet covered by a couple of stagehands whose feet were still visible. That leaves us with the Blob, a single-celled organism from outer space that eats anything it touches, and the Thing from John Carpenter’s horror remake, which absorbs and imitates any living being it gets near. Advantage: The Thing. They’re both equally omnivorous. They’re both equally vulnerable to fire and freezing, which cancels each other out. But the Thing has two tricks up its sleeve (assuming it has grown arms that can wear sleeves, that is). First, the Blob is not very bright — it’s made of one cell, and it’s not a brain cell. The Thing knows how to build a spacecraft out of spare parts it finds in a storage shed, which I bet even that Stephen Hawking guy can’t do. Combine that with the Thing's ability to shapeshift, and eventually it’ll figure out a way to turn into a monster whose stomach can digest even the Blob.

When world-destroyers collide
In this corner: Galactus, perennial Marvel Comics villain
In that corner: Darth Vader, of the “Star Wars” films
And the winner is: Galactus. Vader may have the Death Star, with the ability to destroy whole planets at his nefarious command. But big as it is, the Death Star is still only the size of a small moon. Galactus, on the other hand, literally eats planets for breakfast, and he could crack open the Death Star like he’s making a fried egg. So unless Vader can quickly establish an alliance with the Silver Surfer, the Empire is in trouble. (OK, yes, Galactus has never been in a movie, but I liked this matchup so much I violated my own rule. Sorry.)