Untradeable Single Species: How?

[Kyttias]

How would I go about making a species be untradeable? Basically, I'm going to give the user a free pet at the start, they only get one of this special kind, and it needs to be untradeable and unable to be pounded, because I'll be calculating their progression (for story-driven events) based on the level of that one, special pet. If they were to lose it... my system crumbles.

Do I just add a column in the database to hold a marker saying if its the starter pet? And when its first adopted from the special page, it will get that marker? I could always set it to 'not for trade' on its creation, right? And then check if its the starter pet, and disappear away the option to change its trade status, and the link to pound it, from the pet management page?

Or is there a better way?