Ophiuchus is a constellation that is in the middle of the Scorpius, Sagittarius, Libra, Aquila, Hercules and Serpens constellations. It is often represented as a snake because the name given to it in Ancient Greek meant "serpent-bearer", because it "holds" the serpent, represented by its bordering constellation, Serpens.
The constellation rose to prominence in 2011 and 2016 because astrologers mistakenly believed that NASA had updated the number of Zodiac signs from 12 to 13. The source of this confusion was a NASA educational website that had been updated to include Ophiuchus, in addition to the fact that Ophiuchus is one of the thirteen constellations that does cross the ecliptic.
The correct pronunciation of Ophiuchus is oh-fee-YOU-kuss. The key to pronouncing Ophiuchus correctly is to stress the third syllable, -YOU. A second important note is to remember that "Phi" is pronounced like the word "fee". If you remember these two rules, then you will be able to pronounce Ophiuchus with relative ease.