Basilosaurus isn't as hard to tame as you'd think. It may be surrounded by mantas and sometimes megs, but there's a simple solution; Baryonyx.

Tame a Bary, any level will do. Approach the Basilo and use the tail spin attack, it'll stun the mantas/megs and scare the Basilo away for a few meters, far enough for you to take out every threat with a Bary stun-lock without hurting it further. Once they're dead, all you need is swim towards the Basilo, feed it, and follow it around until it's tamed.

Been doing it this way for years with no problems whatsoever, in my opinion it's the best and safest way to tame it. -Hydro

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