Improving Humunculi

[Cardea]

Lets say you're an Artificer and you make a Homunculus.

You build it as is, without adding HD.

Later on, if you want to have a higher version of that same Homunculus, do you have to make a new one entirely, or do the rules say you can improve the one you've had for [x] amount of time?

[Clistenes]

Lets say you're an Artificer and you make a Homunculus.

You build it as is, without adding HD.

Later on, if you want to have a higher version of that same Homunculus, do you have to make a new one entirely, or do the rules say you can improve the one you've had for [x] amount of time?

An Artificer explicitly can improve them when he/she gains more levels, and you explicitly can improve your already existing homunculus after taking the Improved Homunuculs feat, so....

...I would say that a mage should be able to give more HD to his already existing homunculus, since it's clear there are ways to improve the little buggers once created.