Living Spell Familiar?

[Pyromancer999]

One of my players was creating a new character for a short campaign we're about to do. He came across some Eberron stuff, and fell in love with Living Spells, and somehow wants one of his own. He came up with this story to explain how he got a Living Spell(Acid Splash):

Once, as an apprentice, his character got into a spat with a fellow apprentice about how the character could not cast even the most minor of spells (cantrips). The fellow apprentice bet that the character could not even cast a cantrip at Level Zero, a special area around where the apprentices were being taught.

Level Zero was known for being an area where magical abilities were highly boosted (this took place in the form of a d% roll: 1-10: no enhancements; 11-30: +1 to Caster level; 31-50: +1 to DC of spell, 51-70: +2 to caster level; 71-90: +2 to DC of spell; 91-93: +1 to DC and caster level of spell; 94-96: +2 to DC and caster level of spell; 97-99: +3 to DC and Caster Level of spell; 100: Spell becomes a living spell)

In any case, they both gathered at Level Zero and the character cast Acid Splash, and, in a 1-in-100 chance, it became a Living Spell, that followed him around, serving as his familiar.

So, now the Living Spell serves as a familiar, and I was wondering whether it was overpowered to allow that, and if not, what bonuses it should grant.

[Magicyop]

...maybe slightly overpowered. You might want to tone it down a small bit to make it familiar, and not a monster. For bonus, perhaps +1 damage per damage dice to acid spells cast?

[Pyromancer999]

I ruled the cantrip was cast with caster level of 1, and since it was a level 0 spell, the CR should have been one. However, I changed its size to Tiny, so I supposed it should be good.

Good idea for a bonus, though.

[Magicyop]

Yeah, tiny size will work fine. You could even make caster level scale with the player's level, make the caster level equal to half the player's level? or 1/3rd?

[Pyromancer999]

Maybe, but then there'd need to be a scale, like when its caster level is 1-4, it'd be tiny, then after that it'd move on to the normal scale sizing for a living spell. I'd probably do it at 1/3 level.

Still, almost none of the other familiars receives a similar benefit, so I'm not sure if that should be included.

[Magicyop]

Not necessarily, the size shouldn't need to scale. The problem is, the Acid Splash basically becomes useless at higher levels. Since Acid Splash deals more damager the higher you get, it wouldn't be unreasonable. A more potent Acid Splash doesn't mean a larger Acid Splash.

[Pyromancer999]

The only thing that changes with caster level for Acid Splash is its range.

Also, with the Living Spell template, I'll have to double-check, but I believe that the size changes in accordance to the caster level of the spell