1. Sarutobi's Enma: Enma is the most powerful summoning animal in the early stages of Naruto. He can transform into a staff, becoming Sarutobi's weapon. However, he doesn't appear later on due to the Four-Tails's monkey, Son Goku, taking his place.
2. Sanjouyu, the Salamander: Orochimaru's summoning animal. It has highly poisonous abilities that even Orochimaru himself cannot resist, wearing a gas mask as a result. The depiction of the salamander in Naruto is not entirely accurate, but Orochimaru is still regarded as a demi-god and the one who granted the title of the Sannin.
3. Pain's Dogs: These immortal dogs are summoned by Pain, an adept in the Animal Path.
4. Kurama, the Nine-Tails: Madara Uchiha used his Sharingan to control the Nine-Tails and summon it. During the battle with the First Hokage, it fought alongside Madara. After his defeat, the Nine-Tails were sealed inside the Uzumaki clan. It is one of the most powerful summoning animals.
5. Gedo Mazo: The shell of the Ten-Tails, known as Gedo Mazo, possesses formidable combat abilities despite lacking the chakra of the nine-tailed beasts. It was sealed on the moon, but Madara Uchiha summoned it into the ninja world when he awakened the Rinnegan.