It's about 5,000 times as heavy as a Hamster
In other words, the weight of a Hamster is 0.0002 times 999 kilograms.(for Syrian hamster, a.k.a. golden hamster, a.k.a. Mesocricetus auratus; adult)
An adult Syrian hamster has a typical weight of about 0.20 kilograms. Known for transporting food in the pouches of their cheeks so that they can bury it later, some hamsters can store up to 25 kg of food in their borrows.
It's about 6,000 times as heavy as a Billiard Ball
In other words, 999 kilograms is 6,128.46747610970 times the weight of a Billiard Ball, and the weight of a Billiard Ball is 0.00016317293089965 times that amount.(American-style, WPA specifications)
Per the World Pool-Billiard Association, a billiard ball weight must weigh between 0.15592237718750 kilograms and 0.170097138750 kilograms. According to legend, the difficulty in obtaining elephant ivory for the manufacture of billiard balls in the 19th century inspired the search for a replacement material, which led to the development of the first industrial plastic.
It's about 6,000 times as heavy as a Puck (Hockey)
In other words, 999 kilograms is 6,128.46747610970 times the weight of a Puck (Hockey), and the weight of a Puck (Hockey) is 0.00016317293089965 times that amount.(Ice hockey)
A standard ice hockey puck weighs between 0.15592237718750 kilograms and 0.170097138750 kilograms. Hockey pucks can be shot or passed at speeds of up to 160 kph (99 mph) during games.
It's about 7,000 times as heavy as a Baseball
In other words, 999 kilograms is 6,875.84155856210 times the weight of a Baseball, and the weight of a Baseball is 0.00014543674275838 times that amount.(MLB rules)
Per Major League Baseball rules, a baseball must weigh between 0.1417476156250 kilograms and 0.148834996406250 kilograms. A major league pitcher can throw a baseball at up to 150 kph (91 mph) (with a fastball pitch), with record-setting pitches as fast as 171 kph (106 mph).
It's about 7,500 times as heavy as a Battery (D)
In other words, the weight of a Battery (D) is 0.000135 times 999 kilograms.(Alkaline)
A "D" size battery weighs 0.1350 kilograms. The D size battery is the oldest of the modern battery sizes, first invented by the National Carbon Company in 1898.
It's about one-ten-thousandth as heavy as The Eiffel Tower
In other words, 999 kilograms is 0.00009890 times the weight of The Eiffel Tower, and the weight of The Eiffel Tower is 10,100 times that amount.(a.k.a. La Tour Eiffel) (Paris, France) (total weight)
The Eiffel Tower weighs approximately 10,100,000 kilograms. Architected to be quickly assembled, the Tower contains only 930 cu. meters of solid material.
It's about 10,000 times as heavy as a Deck of Cards
In other words, 999 kilograms is 11,000 times the weight of a Deck of Cards, and the weight of a Deck of Cards is 0.0000910 times that amount.(ISO 216 B8 size, a.k.a. "poker size" 63 x 88 mm, 52-card deck)
A deck of 52 ISO 216 B8-size playing cards weighs 0.094 kilograms. Utilizing nearly 3,700 decks, the record-holding largest card tower was built in early 2010, stood over 3.5 m (11 ft), and weighed over 272 kg.