You can't handle the tooth.

The beaver is North America's deadliest predator. It can fire its explosive front teeth up to thirty meters with unerring precision, and each one packs enough force to down a grizzly bear. Grizzlies are their primary diet, and a beaver can devour a bear carcass in under fifteen minutes. It is hypothesized that this voraciousness evolved to keep other beavers from stealing the kill. A typical beaver eats an entire grizzly every two to three days, due to the need to fuel their hyperactive metabolism.

During winter, beavers hibernate in most areas, getting up about once a month to sleepwalk to a nearby cave and eat the grizzly bear contained within. (Waking a somnambulating beaver is certain death.) The cave often collapses afterwards, due to the seismic destabilization caused by beaver tooth explosions. In areas where global warming has disrupted natural winter patterns and it is no longer cold enough to support hibernation, angry beavers roam the countryside in winter, detonating random targets out of rodential rage. Taxis are particularly popular targets, as their checkered coloration offends the beavers' sense of sight.

In summer, beavers take to the skies, cruising aloft on high-altitude winds by means of their broad, sail-like tails. They scan the terrain beneath them for clumps of trees, which they topple with their teeth, sending dozens of trunks at a time cascading into nearby streams and rivers to dam them out of spite. Early North American loggers used to follow airborne beavers and opportunistically collect the fallen trees they left in their wake. This was a highly dangerous occupation, as the beavers occasionally turned on their followers, raining down fiery death upon them.

The Mount St. Helens explosion was initially believed to be a beaver attack, and news reports hours laters were still mistakenly claiming that it had been a rare simultaneous bombing by a beaver pack. Geologists discredited the theory on the basis that beavers are solitary creatures, mostly because they hate everyone, even other beavers. Mating is difficult for beavers, as they need to close their eyes and hold their noses in order to put up with their sexual partner. A typical litter consists of three to five young beavers, whom the mother promptly abandons to be raised by wolves. The wolves find this practice terrifying, but dare not offend the mother, or she will return to blow them up.

Early attempts to weaponize beavers during the French & Indian War failed miserably, as the damn things are so ornery, but the beavers were quite happy to attack the French on their own, as the latter represented the bulk of the trapper population, and beavers had come to loathe anyone who spoke French. Beaver trapping was a highly dangerous operation, in which the trapper needed to release two grizzly bears simultaneously to take on the beaver from different directions, then quickly attack while the beaver's two explosive teeth were still growing back. Accidentally grouping the two grizzlies close enough to be taken out by a single tooth led to explosive death for the trapper. As a result, beaver fur was outrageously expensive, and King George III's beaver-felt top hat cost the Crown the entire GDP of Ireland for a year and a half.

By the time of the US Civil War, the Union employed weaponized beavers against the Confederacy. This was achieved by having brave souls disparage Southerners within earshot of a beaver, claiming that they had heard them speaking in French. Ideally, the beaver would vaporize the Southerners before getting within hearing range and realizing it had been misled. Beavers proved critical in winning the war, but were later banned as armaments by international weapons treaties after the devastation they wreaked in Atlanta. As a result, the US developed a synthetic form of beaver musk for use as a munition, eventually settling on the formula called Castor-4, or C4 for short, which is substantially less powerful than actual beaver musk, due to the limitations of the treaties.

At over 25kg, beavers are the world's second-largest rodent, after the capybara.[citation needed]