I wouldn't mind what you suggested above:
Let's start on that then.
Rather than immunity to "save or dies" and "save or suck" it'd be closer to say that they only affect a Toon for a few rounds. Something like.
Some Name [Cartoon Elasticity?] (Ex): A toon can not be permanently killed, injured or transformed by any weapon or power. If an attack inflicts a special condition on a toon (stunned, confused, paralysed, dead et cetera), the condition will affect the toon for a maximum of
X rounds, after which the toon fully recovers its abilities and health, even springing back to life if the attack killed the toon. Toons can also recover from any transformation effect, including those that would destroy the toon. A petrified or disintegrated toon will only remain a statue or dust for X rounds before returning to its original form.
What about a
sphere of annihilation, can that destroy a toon?
Since they're only temporarily affected by the "Dead" condition we could give them Fast Healing instead of Regeneration, but I think Regeneration is a better fit.
Regeneration (Ex): A toon regenerates at X hit points per round. If an attack severs a body part, the toon can reattach the part as a standard action. If it can't recover a severed part, the lost part(s) will mysteriously vanish and reappear on the toon Y rounds after it was severed.
Are we going to introduce a "Dip" that can kill a toon? Since they're literally living 3 dimensional pictures, maybe
erase can hurt a toon?
Do we want to include a "massive damage causes temporary body displacement" ability, like the way Daffy Duck's face might end up backwards after he's shot in the face?