It's about as heavy as a Cow.
(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 one-and-three-tenths times as heavy as a Grizzly Bear.
In other words, 680 kilograms is 1.310 times the weight of a Grizzly Bear, and the weight of a Grizzly Bear is 0.7630 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-one-third times as heavy as a Polar Bear.
In other words, the weight of a Polar Bear is 0.7580 times 680 kilograms.(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-a-half times as heavy as a Grand Piano.
It's about one-and-three-fifths times as heavy as a Horse.
In other words, the weight of a Horse is 0.630 times 680 kilograms.(Equus ferus caballus) (Arabian, adult)
n Arabian riding horse (or similar breed) weighs between 380 and 450 kg. During races, horses must carry jockeys and their equipment, which in the Kentucky Derby, for example, can weigh up to 54.4 kg.
It's about two-fifths as heavy as a Car.
In other words, 680 kilograms is 0.41160 times the weight of a Car, and the weight of a Car is 2.430 times that amount.(for 2009 Ford Taurus; automatic transmission; curb weight)
A 2009 Ford Taurus weighs 1,652 kg. The first mass-produced car, the Curved Dash Oldsmobile — introduced in 1901 — weighed just 386 kg.
It's about two-and-a-half times as heavy as a Pig.
In other words, the weight of a Pig is 0.370 times 680 kilograms.(Domestic pig, Sus scrofa domesticus, a.k.a. S. domesticus) (adult)
Domestic pigs weigh between 50 kg and 450 kg. The titular character "Babe the pig" in the 1995 family film was played by 48 different American Yorkshire piglets due to the length of filming and the rate at which piglets reach adulthood.