This is a late reply, but because there is no baby version of the basilisk they end up spawning in full grown but they also spawn in burrowed. Use the Parasaur or a wolf to find out where they are and then drag over a dead body to them. They will unburrow to harvest the body, at that moment quickly run over to them and claim them before they go on a murdering rampage. [they will be unclaimed when they pop out of the ground]

OMG THANK YOU!

Been trying to breed these ♥♥♥♥♥♥♥ for days!

No problem, I had the same issue a few months ago when I was trying to get some baby basilisks. Took a little bit of searching on the internet to find the answer but I was happy to find the results

Unfortunately, this trick does not work for me. :(
We play on Ragnarock.
The hatched basilisks remain invisible.

is this still a thing because im about to try breed them?

so the thing hatched and is invisible in front of me but i could still claim it and use its inventory?
will it still come up for a dead body if i claimed it already?

You have to run into the egg while its hatching in order to make the basilsik spawn up on the ground

if the egg is floating in water when it hatches the basilisk spawns unburrowed