There's a screenshot going around Twitter at the moment that claims that elephants are religious and have been observed to practice "Moon worship" with 50,000 likes and 17,000 retweets, meaning it's time for a good old-fashioned Internet tale debunk.
The tweet in question asks "Why did no one tell me Elephants have religion and observed to Worship the Moon?" and "Who has been keeping this information from me??" to which the answer is probably 1) because it's nonsense and 2) science, because it's nonsense.
The screenshot, taken from Wikipedia, claims:
"Ronald K. Siegel has studied the precursors of religious faith in African elephants and concludes that 'elephants are aware of natural cycles, as they practice "moon worship," waving branches at the waxing moon and engaging in ritual bathing when the moon is full.' Observations by Pliny the Elder also note supposed elephant reverence for the celestial bodies."
In a classic case of "check your sources", if you go to the Wikipedia entry you'll notice that that passage has been removed – due to it being contentious. The citation on the archived page for Ronald K. Siegel's work leads you to The Psychology of Life After Death, written in 1980.
This paper does state that "elephants are aware of natural cycles, as they practice "moon worship," waving branches at the waxing moon and engaging in ritual bathing when the moon is full," but as a reference lists the work of one Ronald K. Siegel, from 1977.
This paper lists C Clair as a reference, who in turn cites Pliny the Elder as the initial source of information. Pliny – while giving us many valuable records from just after BC turned to AD – also wrote down a lot of wildly inaccurate information for us to wade through first. Among other fanciful claims about elephants, he once wrote that elephants and rhinos are natural enemies and that elephants know the "pleasures of love and glory, and, to a degree that is rare among men even, possesses notions of honesty, prudence, and equity".
He also believed that lambs could grow out of the ground like weeds. In essence, this is not the guy you rest your "elephants are religious" claims on, especially if these are the only record of such behavior.
Elephants are cool enough by themselves without having to resort to claiming they worship the Moon. They do indeed show some signs of "mourning" their dead, making repeated visits to the deceased as they decay, and making vocalizations around the dead elephant, showing signs of strong bonds between the animals. They're also lightweights, can understand human gestures, and even mimic human speech.
But they do not worship the Moon, OK?