Once again, Drifters Nexus contains lots of creatures with specific names. There is no way to know which of these are in-jokes, except to recognize them or be "in on the joke".
In general, O-Men is a take-off of Marvel Comics Uncanny X-Men, even though not all of the characters parodied are actually X-Men. X and O are the opposite sides in Tic-Tac-Toe. They are also the letters used to represent "kisses" and "hugs", respectively.
Gob refers to the mouth. All of the Gob creatures feature very prominent mouths.
10 Gallon Voodoo Hat -- Visual: Eagle-Eye McFinny is wearing the hat.
Al' Jabah -- The name sounds like "algebra", and the text deals with multiples.
Annoying Gnats in the Hood -- A "Boyz N the Hood" reference, maybe? The timing may have been right, but I don't think that's it. Gnats are usually refered to as "annoying".
Bagpipes of Fear -- Why would anyone fear bagpipes? Well, maybe because of the infernal racket they make.
Black Locust -- Note that the class is "Tragic". It's a reference to Magic: the Gathering's Black Lotus card. It's also a dig at how much money Wizards of the Coast had and the fact that they could outbid any other gaming company (at the time).
Bruno Smashmouth, Union Boss -- Mob influence in the AFL-CIO (or other unions).
Caddy -- The group of cards, Caddy/Gopher/Golfer, is just a silly combo. Why a Giant? Caddyshack reference?
Captain South America -- Capt. America (an Avenger, not a member of the X-Men). The text box ability is a reference to Cap's mighty Shield.
Carrag the Black -- "Carrag" means "scabby" or "scabby animal" in Manx (from the Isle of Man). (Internet searches reveal the most wonderful useless information).
Delilah Rangoon -- I am amazed at the number of hits for "Delilah Rangoon" on search engines. Most of them have to do with horses, ethnic food, bars & clubs, and movies. Oh, yeah, and card listings. The most infamous "Delilah" cut Samson's hair and made him powerless.
The model for Delilah Rangoon went on to become Playboy's Miss December 1999.
Disgruntled Postal Worker -- Great graphic. It's the very definition of "going postal".
"Eats", Cockroach King -- Visual: his tatoo reads: "Born to Kick Bug".
Golden Fleecer -- Jason stole the Golden Fleece. A fleecer swindles people (in this case out of their destruction
ability). According to Dave Gentzler, Brom painted Keith Parkinson's portrait (returning the favor for Smilin' Jack).
Golfer -- The group of cards, Caddy/Gopher/Golfer, is just a silly combo. This could be a Caddyshack reference.
Gopher -- The group of cards, Caddy/Gopher/Golfer, is just a silly combo. Why is Gopher dressed like Napolean? Is it because he's conquering a golf course? This could be a Caddyshack reference.
Initiate of Entropy -- If you think about it, "initiate" of "entropy" is an oxymoron.
Ix, Overlord of the Waters -- "IX" is the roman numeral for "9". Ix was the Mayan giant that held up the sky (1 of 4).
Little Voodoo Hat -- Visual: Eagle-Eye McFinny is wearing the hat.
Lizards on the Toast -- Double pun: Wizards of the Coast has so much money that they probably are "on the toast" of the town. (Whether or not they're lizards is a different debate altogether.)
Longshot Louie -- This one could be a total co-incidence but in the SF novel Ringworld, Louie is the navigator of the ship the Longshot. The visual shows a creature with a sextant (for navigation) and there are stars visable.
Maitz Motel -- Painted by Don Maitz, a pun on the Bates Motel of "Psycho" fame.
Medallion of Skyphos -- "Skyphos" is a drinking cup.
Medicine Man -- Although they're "in tune" with spirits, Medicine Men are usually people.
Mighty Tiki God -- A reference to MTV. [DG]
Oscar the Wonder Chimp -- Don't know any famous chimps. Takeoff of Rex the Wonder Dog?
Phil, Bar Fly -- "Bar flies" are usually people, not bugs. Apparently, artist Phil Foglio is also a barfly, and this card is based on him, and done in his style. (Foglio is not one of the Guardians artists.)
Professor Heisenburg -- Reference to Heisenburg's Uncertainty principle.
Rock of Far Rolling -- Rock & Roll will always be, it'll go down in history . . . and Rolling Rock is yet another beer reference.
Rosetta Stone -- The key discovery at "translating" hieroglyphics.
Saboteurs -- Champs is pictured.
Shin Chois, Third Disciple -- Looks like Annie Lennox of the Eurythmics. [DG]
Small Mox -- Reference to Magic's "Mox" cards combined with a "smallpox" pun.
Soggybottom Gertz -- Needs to wear Depends?
Sewage Back Up -- Lots of grafitti, including "Ploogak Stinks" and "Tweezle was here" (though it looks like "Tweezle" is misspelled.)
Tanniker Smith -- I'd love to track this one down. It sounds like something out of pulp SF, perhaps E. E. Doc Smith. Anyone?
(Note: Obviously, I like the name because I've usurped it and have been using it for over 10 years now. It was even my badge name at Lunacon once.)
The Amazing Cider-Man -- Spider-Man (not a member of the X-Men). Visual: web shooters supply beer (cider).
The Maitz Motel -- Maitz is the card's artist as opposed to Bates Motel from the movie Psycho.
Tiger Baloo -- The most obvious reference is to "Cat Baloo". In Disney's "The Jungle Book" (and possibly Kipling's version as well), Baloo was a bear. Shere Khan was the tiger. This card predates Tiger Woods raise to fame in the golf world (so no bonus for Woods. Or Irons.)
Tree Ogre -- Bears a lot of resemblance to the Ploog's Polar Ice Ogre, doesn't it? The wrong sketch was sent to Shaw. The mistake wasn't discovered until too late. [DG]
Uras, Overlord of Mountains -- Accidental pun: whenever you beat it in combat, announce loudly, "Aha! I whupped Uras!"
Urufa, Queen of Goblins -- "Urufa" my goblins, "Irufa" you face. (Okay, I'm reaching for that one.) Visually, she's the only green goblin in the game. Maybe Cider-Man will challenge her.
Voodoo Hat -- Visual: Eagle-Eye McFinny is wearing the hat.
Wheel of Law -- "Wheels of justice" reference? More likely, the try-your-luck justice as seen in Mad Max Beyond Thunderdome. Or maybe someone just liked watching "Wheel of Fortune" on TV.
Woolverine -- Double pun: Wolverine of the X-Men; also it's literally a "wolf in sheep's clothing".
You Can't See Me, I'm a Vampire -- Bradstreet, the artist that did this card, worked on Vampire: the Masquerade. And the kid's looking right at him. Dave Gentzler had an interesting commentary on it regarding LARPS Vampire players at cons. When I find a copy of it, I'll post it here.
Zelda, Bag Lady Bug -- She might've been a "Bug Lady" originally, but the pun doesn't work as well.