Yes. Though you'll have to give careful thought as to why it came about.
With regards to energy: This doesn't actually matter all too much. All more energy means is that things happen faster. If you look at the competition for light in rainforests or for a good spot next to the vent in marine thermal vent environments you'll see competition that is no less vicious just for being slow. Ants end up in wars that would make medieval kings question the existence of god. Microbial colonies use chemical weapons against each other. Even ivy will literally suck the life out of it's host. If you want these creatures to be a threat to humans then they'll need a decent energy source, but don't go thinking that slow means nice.
With regards to reproduction: It's all about making sure that you are the one that comes out on top, not anybody else. To that end how vicious you are really doesn't matter, as long as you're only vicious to things that aren't your progeny/going to mate with you. Thank of it this way: In any fight the victor is going to be the one that reproduces. The more vicious creatures get more food and have the chance to reproduce: the less vicious creatures... don't.
The biggest issue here is why. Why has your biosphere evolved to the point where literally everything has teeth? For the answer to that we need to look at what drives things to be/not be vicious here.
Plants here aren't vicious: unless you look at ones that grow in resource starved or high-competition environments: then the knives come out. The reason for this is that their foodstuff (light) is comparatively plentiful. They don't have to compete with each other for it. If they are in an environment where there isn't enough to go around then you'll see various survival strategies arriving. In the jungle, for example, where space and sunlight are at a premium this takes the form of trying to block the sunlight from reaching other plants (as that's the resource that's required) or killing for nutrients that other plants may already have leached. In the desert water hoarding is the norm: and some plants and creatures develop stunningly dangerous ways of defending their stash. For your world you'll want to make sure that there are plenty of most resources, but also that every creature is competing for the same scarce resource.
Your animals are much simpler. Why are they vicious? It's the only way to survive. The only issue here is that groups that co-operate with each other outcompete those that don't. In the short term there may be a downside, but in the long run the group (which may be composed of multiple species that don't try to kill each other and instead only kill plants) will come out on top. So you need a way to stop co-operation being advantageous in the long run.
This is the big one. If an environment is stable then a species has time to specialise. Omnivores become herbivores/predators. Predators become hunters/scavengers. The scavengers are no longer in conflict with the omnivores, and so they don't try to kill each other. Avoiding stability gives no one species a chance to specialise in any way that doesn't involve ripping resources out of the cold dead mandibles of their competition.
If your world is constantly beset by natural disasters (high vulcanism or extreme weather associated with high solar energy input) you create a situation where no stable equilibrium can emerge, there is no long term for co-operation to be advantageous over and resources, though plentiful, are often torn away by Mother Nature. This will turn the brief pools of respite from the chaos into vicious gladiatorial arenas where only the most brutal and adaptable creatures can thrive. Hoarding behaviours are pointless, as your work squirrelling away resources for next year can all be undone with a single tornado, so you may as well live fast, kill as much of the competition as you can and lay your eggs in the corpses, trusting that your young will survive long enough to evade the next apocalyptic event.
Oh, and if any of your young do survive and come back to meet you: They'll be trying to kill you before you eat their prey. So kill them first.