However, some things are so odd that they can leave even the most professional fishermen scratching their heads.
Case in point: Recently, two men in Primorsky Krai in southeast Russia discovered what appeared to be a terrifying-looking two-mouthed mutant fish.
It wasn't clear if the marine animal was dead or alive when it was caught.
The two fishermen were so fascinated by the peculiarity of the fish, that they started documenting it on film.
One of the fishermen, who made the bizarre catch, can be heard saying, "We caught some kind of monster."
Here's what some internet users had to say about the odd creature: "Oh boy! You really know how to ruin my appetite," Papa Karlo (Kollodi) said, according to Daily Mail.
"Everything seems to be mutating in this world," said a user name Galina Ignatenko. "The nature is avenging for people ruining it."
There was one person who went as far as speculating that a nuclear disaster in 2011, presumably the Fukushima Daiichi nuclear disaster, was responsible for the fish's appearance.
"This is all possible thanks to Fukushima explosion," they wrote.
In December, another Russian fisherman, Roman Fedortsov, came across equally mysterious sea creatures, including a creepy ghost shark also known as a chimaera, a gigantic "sea spider" with long legs roughly the size of a human hand, and a frilled shark, also known as the elusive eel-like shark, with rows of terrifying teeth.
Banner/Thumbnail: Reuters / Phil Noble