I'm looking to design a template that would imbue a creature with one or more spells that trigger upon a successful attack. I'm just unsure of how much to price the template's CR adjustment at
Template: Spellbound Creature
Special Attacks
Spellbound Attacks (Su): A creature hit by a spellbound creature's natural attack is affected by the chosen spell(s). Saves apply as normal for the spell, the DC being 10 + spell level + Cha modifier.
So for example:
Emerald Stinger
Spellbound (acid splash) Giant Wasp
CR 4(?) (XP 800)
N Large vermin
Init +1; Senses darkvision 60 ft.; Perception +9
DEFENSE
AC 14, touch 10, flat-footed 13; (+1 Dex, +4 natural, –1 size)
hp 34 (4d8+16)
Fort +8, Ref +2, Will +2
Immune mind-affecting effects
OFFENSE
Speed 20 ft., fly 60 ft. (good)
Melee sting +6 (1d8+6 plus poison plus 1d3 acid)
Space 10 ft.; Reach 5 ft.
Special Attacks: spellbound attacks (acid splash)
STATISTICS
Str 18, Dex 12, Con 18, Int —, Wis 13, Cha 11
Base Atk +3; CMB +8; CMD 19
Skills Fly +3, Perception +9; Racial Modifiers +8 Perception
SPECIAL ABILITIES
Poison (Ex)
Sting—injury; save Fort DC 18; frequency 1/round for 6 rounds; effect 1d2 Dexterity damage; cure 1 save. The save DC is Constitution-based, and includes a +2 racial bonus.
Spellbound Attacks (Acid Splash) (Su): A creature hit by an Emerald Stinger's sting attack is affected by the acid splash spell; the creature suffers normal sting damage as well as 1d3 additional acid damage.