It's about one-and-nine-tenths times as heavy as a Polar Bear
In other words, 999 kilograms is 1.940 times the weight of a Polar Bear, and the weight of a Polar Bear is 0.5150 times that amount.(Ursus maritimus) (adult, male)
An adult, male polar bear weighs between 352 and 680 kg. Polar bears are so heavily insulated by their 9.9 cm (3.9 in) layer of blubber that they are often difficult to detect using infrared photography sensors.
It's about one-and-nine-tenths times as heavy as a Grizzly Bear
In other words, 999 kilograms is 1.920 times the weight of a Grizzly Bear, and the weight of a Grizzly Bear is 0.5210 times that amount.(a.k.a. brown bear, a.k.a. silver bear, Ursus arctos horribilis) (Adult, male, coastal area population average)
An adult, male grizzly bear from a coastal area (where food is plentiful) can weigh up to 521 kg. In spite of their tremendous size, grizzly bears can run at speeds of up to 55 kph (34 mph).
It's about one-and-a-half times as heavy as a Cow
In other words, the weight of a Cow is 0.670 times 999 kilograms.(for Holstein, a.k.a. Holstein Friesian, a.k.a. Friesian, Bos primigenius) (adult, heifer)
A mature Holstein cow (the well-known black-and-white, spotted breed of cow) typically weighs 680 kg. President William Howard Taft (1909 - 1913) kept a Holstein cow named Pauline Wayne on the White House grounds — a gift from a Wisconsin senator and the source of the First Family's milk.
It's about three-fifths as heavy as a Car
It's about half as heavy as a Giraffe
In other words, 999 kilograms is 0.5180 times the weight of a Giraffe, and the weight of a Giraffe is 1.930 times that amount.(Giraffa camelopardalis reticulata) (adult, male, maximum of range)
An adult, male giraffe can weigh up to 1,930 kg. Reaching 5.5 m (18 ft) in height by adulthood, giraffe calves can grow as much as 3 cm (1 in) per day.
It's about half as heavy as a Rhinoceros
In other words, 999 kilograms is 0.480 times the weight of a Rhinoceros, and the weight of a Rhinoceros is 2.10 times that amount.(for Black rhinoceros, Diceros bicornis) (Adult, male)
An adult black rhinoceros weighs between 1,400 and 2,800 kg. Rhinoceros are extremely aggressive — nearly one of every two males will die as a result of fighting with other rhinoceros.
It's about two-fifths as heavy as The Tongue of a Blue Whale
In other words, 999 kilograms is 0.370 times the weight of The Tongue of a Blue Whale, and the weight of The Tongue of a Blue Whale is 2.70 times that amount.(Balaenoptera musculus) (adult)
The tongue of a Blue Whale can weigh up to 2,700 kilograms. Despite their tremendous size, blue whales feed almost exclusively on tiny crustaceans called krill and cannot swallow anything much larger than a beach ball.