Once I found one while playing the island at level 92. It took awhile but I eventually got it down. But while I was putting meat in its inventory I realized I must have accidentally hit it because the taming effectiveness was at 88% instead of 99%

Be careful if you have a tamed megalodon or two following your raft. Wild megas will agro your tamed ones and once one dies (tamed or wild) they start to swarm which means yours are as good as dead.

Avoid this animal in the wild as it is aggressive. But once tamed they make a good water defense for underwater or island bases, both pvp and pve

Build a behemoth water pen, then open a gate and lure one in. Then simply shut the gate and tranq it out! I'm taking two right now!