Answer:
Looks like a hippo crossed with a unicorn.
A mysterious, fantastic creature, It has one defining feature, And for humans at their worst, In their eyes it's just a horse
In all the world, none can compare, to this tiny weaver, his deadly cloth so silky and fair.
Edible beach crawler served at seafood restaurants, similar to a lobster, but quite different.
For our ambrosia we were blessed, By Jupiter, with a sting of death. Though our might, to some is jest, We have quelled the dragon's breath. Who are we?
All about, but cannot be seen, Can be captured, cannot be held, No throat, but can be heard. Who am I?