The term "strongest animal" can be misleading, but most often it refers to how much an animal can lift relative to its own weight. It was thought that the rhinoceros beetle was the world's strongest by this standard, capable of lifting 850 times its own weight. This is comparable to a 150 lb (68 kg) human lifting a 67 ton (about 60.78 metric tons) Abrams tank. Some of the largest rhinoceros beetles weigh 4.23 ounces (120 grams), making them capable of carrying about 220 lbs (100 kg). This means that a strong rhinoceros beetle would be capable of carrying a heavy man.
In 2007, Michael Heethoff and Lars Koerner measured the strength of a tropical mite, Archegozetes longisetosus, finding it has a pull force equal to 1,150 times its own weight, five times more than expected for an organism of its size (1 mm, 100 µg). As this study was the first to measure microarthropod claw forces, there are probably many other mites who might compete for the title of strongest. To put this strength in human terms, this would be like a 150 lb (68 kg) human lifting an 86 ton (78 metric ton) tank, or an elephant with a tower of 1,150 elephants on its back.
The strongest animal on land in terms of absolute strength is likely the African bush elephant, whose weight can range up to 13 tons (11.79 metric tons), and whose carrying capacity is at least 5 tons (4.53 metric tons). Despite this, African bush elephants are afraid of some tiny insects, like honey bees. When scared or upset, an African bush elephant can run at 25 mph (40 km/h), which gives an idea of its strength.
In general, the strongest animal is the blue whale, weighing above 209 tons (189.6 metric tons), with a length of 100 ft (30 m). It can travel up to 30 mph (50 km/h) in short bursts. The kinetic energy of a whale at such a speed probably outclasses any other animal by an order of magnitude.
Historically, some of the largest dinosaurs (like Brachiosaurus or Supersaurus) were stronger than any living animal.