So these guys are a permanent tame. When doing a force tame after failing to tame it normally, you actually do need those cannonballs to hit it in the face. I also checked out the possibility with darts during the failed tamed, either the command removed all torpor or it is resistant to darts. You can ride on its bare back once tamed, hence why there is only a platform saddle engram. I highly suggest investing in a large dino dismount dock if you want to safely get off its back. For reference for The Isle folks the titanosaur is roughly the size of a pue.

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