Evolution isn't perfect. Just as the Kennedy family can produce a Ted, some noble species go down the wrong genetic path and what used to be the Tyrannosaurus Rex can wind up as a modern chicken.
Here are six kickass creatures that evolution apparently decided were just too awesome to exist and then, to add insult to injury, evolved them into the crappiest replacements possible.
Used to be ...
The Hyaenodon gigas was the size of a horse, with jaws as long as an alligator's, specially designed to tear away flesh. They had an acute sense of smell unmatched in the prehistoric world and weighed upwards of a quarter of a ton. They were swift, effective killing machines which traveled in packs and could, as a group, take down anything.
Remember the Velociraptor from Jurassic Park? Give it a sophisticated mammalian brain, warm blood and add a substantial amount of pure animal muscle and you have the Hyaenodon.
The Crappy Evolutionary Spin-off:
The fuzzy little raccoon. Despite its adorable eyes and overall cuteness, this animal doesn't have a lot going for it (though if it was domesticated it'd probably be more popular then dogs, what with their adorable little people-hands).
Far from being the dominant predator on Earth, wandering in vicious packs, raccoons spend their days as minor annoyances who tip over garbage cans. Rather then savaging the carcass of a fresh kill, raccoons hunt for that last bit of orange dust at the bottom of a discarded bag of Cheetos.
How the hell did that happen?
The Hyenadon lost the mammalian evolutionary arms race to larger, more merciless killing machines with more teeth and more muscle, slowly leaving behind only the ones small enough and smart (and cowardly) enough to hide. That's how in the game of evolution, the loser winds up extinct or reduced to stealing doormats.