Nilbog over at WotC, wrote up this version of the Easter Bunny. I'm reposting it here because I think it fits thematically. I'm updating it it a little.
Edit: I changed around the feats and added the missing feat and moved some abilities from special attacks to special qualities. I removed the flaming weapons which don't fit thematically and added the claws, and thrown egg as a projectile weapon. I also added the rotten egg and chocolate egg, which fit themacally. I removed some spell-like abilities because they worked better in egg form. I also limited the exploding egg to once per encounter as it is supposed to be a "last ditch" defense. Last of all, I also updated the Basket of Never Ending Prismatic Eggs a bit.
Medium Outsider (Chaotic, Extraplanar, Good)
Hit Dice: 10d8+20 (65 hp)
Speed: 40 ft.
Armor Class: 18 (+4 Dex, +4 natural), touch 14, flat-footed 14
Base Attack/Grapple: +10/+12
Attack: Bite +13 melee (1d6+2) or egg + 14 ranged (1d2 plus blindness)
Full Attack: Bite +13 melee (1d6+2) and 2 claws +8 melee (1d4+2), or egg + 14 ranged (1d2 plus blindness)
Space/Reach: 5 ft./5 ft.
Special Attacks: Egg throwing
Special Qualities: Darkvision 60 ft., DR 5/magic, mystic eggs, spell-like abilities
Saves: Fort +10, Ref +11, Will +9
Abilities: Str 15, Dex 18, Con 15, Int 10, Wis 13, Cha 14
Skills: Appraise +13, Bluff +15, Diplomacy +15, Jump +19, Listen +16, Search +14, Sense Motive +14, Spot +16
Feats: Alertness, Point Blank Shot (eggs), Weapon Focus (bite and claws)
Environment: Any land and underground
Challenge Rating: 6
Alignment: Always chaotic good
Advancement: 11-20 HD (Medium), 21-30 HD (Large)
Level Adjustment: -
An Easter Bunny appears to be a 7-foot-tall bipedal rabbit, carrying a basket of painted chicken eggs over one shoulder.
Easter Bunnies seem to exist to bring joy, cheer, and unpredictability. They give eggs as gifts, then vanish, but the recipients of these eggs seem completely random.
Easter Bunnies prefer to throw eggs at their enemies from a distance rather than engage in personal combat. They will use their exploding egg if combat goes badly and will then escape using their dimension door ability.
Egg Throwing (Ex): An Easter Bunny can throw an egg up to 60 feet as a standard action. Anyone hit by an egg takes 1d2 points of damage and is blinded until he wipes the goo off [a standard action]. Eyeless creatures are unaffected by the blindness.
Mystic Eggs (Su): An Easter Bunny can create several magical effects with the eggs in its basket. Despite the appearance, the basket is part of the Easter Bunny and cannot be disarmed or otherwise removed.
Chocolate: An Easter Bunny can produce one chocolate egg per round as a free action. When a chocolate egg is eaten (a standard action), the target gains a +1 morale bonus on attack rolls and on saving throws against fear effects. This is one type of egg an Easter Bunny may give as a gift.
Explosion: Once per encounter, an Easter Bunny can produce an exploding egg. As a last-ditch defense, an Easter Bunny can throw an exploding egg as a standard action. The egg explodes up to 60 feet away in a 10-foot radius burst of flames, dealing 4d8 points of fire damage to anyone within range. These are never given as gifts.
Healing: An Easter Bunny can produce up to two healing eggs per round as a free action. Each egg, when broken (a standard action), heals the breaker as a cure light wounds spell (5th caster level). This is one type of egg the Easter Bunny may give as a gift.
Jewel: An Easter Bunny can produce up to two jewel eggs per round as a free action. A jewel egg is non-magical, but is worth 100 gold pieces. This is one type of egg the Easter Bunny may give as a gift.
Rotten Egg: An Easter Bunny can produce an egg once every 4 rounds that acts as a stinking cloud effect. An Easter Bunny is immune to the stench of his egg and of the egg of any other Easter Bunny. These are never given as gifts.
Spell-like Abilities: At will - dimension door . 3/day - aid. Caster level = 1/2 x HD (5th for a 10-HD Easter Bunny).
Skills: An Easter Bunny has a +4 racial bonus to Jump checks.
This idea comes from ML3 over at EnWorld:
The Basket of Never Ending Prismatic Eggs.
In the hands of any humanoid, the basket provides an unending supply of brightly colored eggs. Any creature eating one of these eggs gains a +1 on all morale checks and heals 1d4 points of damage per egg eaten. The eggs are as nutritious and filling as normal chicken eggs.
In the hands of the Easter Bunny, the eggs can also be used as weapons if necessary. Each egg can be used as if it were a prismatic sphere, each color acheiving a different effect.