It's about one-and-one-tenth times as heavy as a Hippopotamus.
In other words, 4,000,000 grams is 1.07 times the weight of a Hippopotamus, and the weight of a Hippopotamus is 0.9350 times that amount.(Hippopotamus amphibius) (adult, male)
The average weight of an adult male hippopotamus ranges from 3,750,000 grams. 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 one-and-a-half times as heavy as The Tongue of a Blue Whale.
In other words, the weight of The Tongue of a Blue Whale is 0.670 times 4,000,000 grams.(Balaenoptera musculus) (adult)
The tongue of a Blue Whale can weigh up to 2,700,000 grams. Despite their tremendous size, blue whales feed almost exclusively on tiny crustaceans called krill and cannot swallow anything much larger than a beach ball.
It's about two-thirds as heavy as an Elephant.
In other words, the weight of an Elephant is 1.50 times 4,000,000 grams.(for African bush elephant, Loxodonta africana) (Adult, bull)
A bull African bush elephant weighs about 6,100,000 grams. 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 4,000,000 grams
It's about three-fifths as heavy as a Tyrannosaurus rex.
In other words, 4,000,000 grams is 0.630 times the weight of a Tyrannosaurus rex, and the weight of a Tyrannosaurus rex is 1.60 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 6,400,000 grams 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-and-nine-tenths times as heavy as a Rhinoceros.
In other words, the weight of a Rhinoceros is 0.530 times 4,000,000 grams.(for Black rhinoceros, Diceros bicornis) (Adult, male)
An adult black rhinoceros weighs between 2,100,000 grams. Rhinoceros are extremely aggressive — nearly one of every two males will die as a result of fighting with other rhinoceros.
It's about two times as heavy as a Giraffe.
In other words, 4,000,000 grams is 2.07 times the weight of a Giraffe, and the weight of a Giraffe is 0.4830 times that amount.(Giraffa camelopardalis reticulata) (adult, male, maximum of range)
An adult, male giraffe can weigh up to 1,930,000 grams. 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 two-and-a-half times as heavy as a Car.
In other words, 4,000,000 grams is 2.4210 times the weight of a Car, and the weight of a Car is 0.41310 times that amount.(for 2009 Ford Taurus; automatic transmission; curb weight)
A 2009 Ford Taurus weighs 1,652,000 grams. The first mass-produced car, the Curved Dash Oldsmobile — introduced in 1901 — weighed just 386,000 grams.