Ohhhh what's three times the size of an elephant, over 500 years old, and lives under the sea? Big Momma! She is a massive protites coral that's 6.4 m (21 ft) high and 41.8 m (135 ft) around at the base; her age was estimated based on samples of her skeletal core and the fact that porites corals only grow about 1 cm (0.39 in) per year.
(Image: 'Big Momma', a Porites species of coral (left) and a diver (right) by Wendy Cover via NOAA)
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