Largest and heaviest animals

The largest animal currently alive is the blue whale. The maximum recorded weight was 190 tonnes for a specimen measuring 27.6 metres (91 ft), whereas longer ones, up to 33.6 metres (110 ft), have been recorded but not weighed. It is estimated, this individual could have a mass of 250 tonnes or more. The longest non-colonial animal is the lion's mane jellyfish (37 m, 120 ft).

In 2023, paleontologists estimated that the extinct whale Perucetus, discovered in Peru, may have outweighed the blue whale, with a mass of 85 to 340 t (94–375 short tons; 84–335 long tons). However more recent studies suggest this whale was much smaller than previous estimates putting its weight at 60 to 113 tonnes. While controversial, estimates for the weight of the sauropod Bruhathkayosaurus suggest it was around 110–170 tons, with the highest estimate being 240 tons, if scaled with Patagotitan, although actual fossil remains no longer exist, and that estimation is based on described dimensions in 1987. The upper estimates of weight for these two prehistoric animals would have easily rivaled or exceeded the blue whale.

The African bush elephant (Loxodonta africana) is the largest living land animal. A native of various open habitats in sub-Saharan Africa, males weigh about 6.0 tonnes (13,200 lb) on average. The largest elephant ever recorded was shot in Angola in 1974. It was a male measuring 10.67 metres (35.0 ft) from trunk to tail and 4.17 metres (13.7 ft) lying on its side in a projected line from the highest point of the shoulder, to the base of the forefoot, indicating a standing shoulder height of 3.96 metres (13.0 ft). This male had a computed weight of 10.4 tonnes.