I bet every single one of you as a kid drew monsters, was interested in monsters or collected something monster related. And I bet secretly you are all still like this!

So put it to good use. You don't have to draw anything, nor do you particularly have to put much effort into this. All I am looking for is simple ideas for monsters.
This includes a name, rough description/appearance (including size, will expand on this below), and what the monster acts like. Optional things are things like what does the monster fight like, can it breath fire or maybe it shoots out needles or something totally crazy.

Anyway, for size, it comes in the following categories.

Fine: This is tiny, like an insect.
Diminuative: Very small, a rat or small bird.
Tiny: Small, along the lines of a cat.
Small: As the name implies, small, about the size of a large dog.
Medium: Human size. (In technical terms, this is 32x32 pixels in size)
Large: The size of a large animal, such as a full grown bear, cow, horse and so on. (64x64 pixels)
Huge: Massive animals, an elephant would be a good example. (96z96 pixels)
Gargantuan: This is stupidly big. No animal alive is this big, something like King Kong would be an example of this. (128x128 pixels)
Collosal: Basically anything bigger than Gargantuan. Godzilla is an example of this (as tall as skyscrapers). (160x160 pixels and larger)

Examples include...

Thunderhoof
Size: Large
A blue-gray rhino with a large horn, when it charges it's hoofs make a very loud, almost ear shattering thumping sound, hence the name Thunderhoof.

Arrowk
Size: Huge
A massive hawk, has a very steamlined appearance, with a sharp beak and razor sharp feathers. Likes flying at high speeds for no apparent reason.

Tyrantsaurus
Size: Huge
A massive, T-Rex like dinosaur, but has well developed, muscular arms. Enjoys tenderising it's prey before devouring them whole.

Yamata
Size: Collosal (mountain sized)
A massive eight headed snake, big enough to coil around a mountain. Enjoys drinking beer.