I’m a fan of the capybara. They’re the largest rodents in the world and look like giant guinea pigs. They’re partially aquatic, apparently only like to mate and poop in water, and because of their aquatic nature, are OK to eat during Lent! (Though, according to my googling, is only practiced by some people in Venezuela).
My wife raises wallabies (what are they? macropods or something?). They ain’t so bad. Pretty quiet and not too destructive. Tame ones are kinda cute.
But adult males have the most disgusting trait I have ever seen in the animal kingdom. First of all, thier balls are above the dicks and the dicks are disgusting!
There I was, pulling out sticker bushes by the fence. There is Boomer, on the other side, sizing up one of the females. His knob is poking straight down, then it bends and straightens out again several times, like a finger motioning towards the female for her to “come and get it”!
Most disreputable thing I’ve ever seen!
Is it too late to vote for the chupacabra?
It howls!
It barks!
It eats meat!
The carniverous Grasshopper Mouse
Agreed 
They also always give birth to identical quadruplets!
In the extinct catagory, I have always liked Terror Birds:
http://www.kenozoicum.nl/website%20mega%20predators/terror%20bird.html
Ever since Smithsonian Magazine had a cover article on them 20 years or so ago, I’ve been fascinated by meerkats. They have a fascinating social structure, with babysitters, guards, etc.
For pure animal cuteness, there’s always the ring-tailed lemur.
And no, I’m not usually so fascinated by the word fascinated. Duh.
There’s nothing especially unusual about saigas (other than the way they look), but I think they’re pretty neat.
I am also a fan of alpacas, but I’m not sure they fit into the ‘weird’ category. I guess weird as pets, but not as animals. So never mind that.
I also think slime molds are incredibly bizarre and interesting. It’s goo, then it congeals into a mass that slinky-walks around.
And what a cool name!
Large creatures with four toes on each front foot, three on each back foot, a flexible snout, closely related to rhinos and horses, love bananas, swim well, walk on bottom of rivers and ponds, chirp and squeak like birds, are divided into 4 species, have stripes and spots at birth, and live in jungles and forests of Central and South America.
Oh, and they’re all endangered. 
I just need to point out one more, the Indricothere. World’s largest land mammal EVAH. Looks like the love child of a rhino and a giraffe. I’d give my left arm and a Snickers bar to see a herd of these beasts move across the plains.
First item at www.kokogiak.com/megafauna/strange.asp
Actually, most of the creatures on that page are pretty dang cool.
The Dun King
Buffalo Tree Hopper Gnarly little bugs that love my tomato plants. Here’s a color photo They look like a cross between a rhinoceros and a WWI tank. Even though I have to battle them, I can’t help but love how cute they are. They don’t hurt the tomatos specifically, but they stress the plants and attract ants.
My vote has to be for the pitohui birds. It’s the only bird (well, family of birds) in the world known to be toxic. Yes, you heard me right, there is such thing as a poisonous bird. Touching its feathers bings about a numbing tingling sensation. Very cool. And they’re actually quite cute birds too .
Holy cow. Those guys could give the Stymphalian birds a run for their money.
Beat me to it. I love these guys and thought about choosing Capybara for a user name, but someone beat me to that too.
So, I’ll settle for the Javelina, a critter who has fascinated me ever since I almost crashed into one on a walk in the desert near Tucson.
Hey, if the Jesuits say they’re fish, they MUST be fish. I mean, if you can’t trust Jesuits… :eek: 
My favorite odd critters are both bats.
First, the ever-popular Vampire Bat. Not only is this the only mammal (AFAIK) that has evolved to live solely on a diet of blood, it’s also got some of the wierdest kidneys going: These critters, while feeding from a host actually piss most of the time - water is heavy, and has no nutritional value in itself, so they ditch as much of the water weight of the blood as possible. That means their kidneys are, at that time, among the most wasteful of all mammals. (I’m not 100% certain, but I think some aquatic mammals actually piss more electrolytes in their urine than the vamps do at this time.) Then, when the bat gets to its lair to digest the meal, the kidneys go to the opposite extreme, recoving as much water from the bat’s urine as most desert rodents do, so digesting time urine is more of a paste than a fluid. Coool - split personality kidneys!!!
Then, if you think those critters are weird, take a look over here: The Fisher Bats. Yes, this is a bat that is evolved to eat fish. Not so interesting you say? Well, they can fly with their hips rotated 180 degrees, and then flex their legs to bring their catch of a smallish fish close to their body for flying away. Sounds simple, but think about how few animals can rotate their hips more than about 70 degrees…
Kinkajou gets my vote.
It’s commonly believed now that that description of Hallucigenia is upside down, and that they are possibly most closely related to the Onychophora phylum.
For my own interesting critter, I would submit the tree hyrax, arboreal and hooved!
When I was a kid I saw these in a zoo, before I had ever heard of them. I was astonished at the giant guinea pigs! If they had bugs the size of buffalo I wouldn’t have been more shocked and surprised.