It's about one-fifth as heavy as a Hippopotamus
In other words, 680 kilograms is 0.1810 times the weight of a Hippopotamus, and the weight of a Hippopotamus is 5.520 times that amount.(Hippopotamus amphibius) (adult, male)
The average weight of an adult male hippopotamus ranges from 3,000 to 4,500 kg. Appearances to the contrary, adult hippos cannot swim or float in water; they actually move by leaping and walking across lake bottoms at about 8 kph (5 mph).
It's about eight times as heavy as a Kangaroo
It's about one-tenth as heavy as a Tyrannosaurus rex
In other words, 680 kilograms is 0.110 times the weight of a Tyrannosaurus rex, and the weight of a Tyrannosaurus rex is 9.10 times that amount.(for FMNH PR2081, a.k.a. "Sue") (a.k.a. Tyrannosaurus, a.k.a. T-Rex) (estimated live weight)
The notable Tyrannosaurus specimen housed at the Field Museum of Natural History in Chicago, Illinois, "Sue," is estimated to have weighed about 6,400 kilograms while alive. A renowned predator in popular culture, the teeth of tyrannosaurus rex were up to 33.02 cm (13 in) long.
It's about one-tenth as heavy as an Elephant
In other words, 680 kilograms is 0.110 times the weight of an Elephant, and the weight of an Elephant is 9.10 times that amount.(for African bush elephant, Loxodonta africana) (Adult, bull)
A bull African bush elephant weighs about 6,100 kg. Among African elephants, both males and females have tusks (whereas female Asian elephants, Elephas maximus, do not have tusks) which can grow to 3 m (10 ft) and typically weigh about 4,000 kg
It's about nine-and-a-half times as heavy as a Beer Keg
In other words, 680 kilograms is 9.340 times the weight of a Beer Keg, and the weight of a Beer Keg is 0.10710 times that amount.(for US half-barrel, full keg; draft beer; including keg itself, stainless steel)
A typical, half-barrel beer keg weighs 72.80 kg when full. A keg of this size contains 15.5 gallons of beer, or the equivalent of 6.8 cases.
It's about fourteen times as heavy as an Octopus
In other words, the weight of an Octopus is 0.071 times 680 kilograms.(for Giant Pacific Octopus, Enteroctopus) (Adult, average)
The adult North Pacific Giant Octopus usually weighs around 50 kg. It is the largest octopus species and is known for its considerable intelligence, including the ability to open jars, solve mazes, and mimic other octopuses.
It's about fifteen-and-a-half times as heavy as a Toilet
In other words, the weight of a Toilet is 0.0641 times 680 kilograms.(KOHLER Round front sitting flush toilet, model #K-11471-0)
The weight of a typical round front sitting flush toilet is 43.6 kg. The Indian town of Musiri in Tamil Nadu state features the world's only paying toilet, which rewards its users up to 10¢ Indian (10 paisas) per visit and uses the waste for compost and fertilizer.