Giant Rhino

This rhinoceros was a summon of Pain.

Appearance
Resembling a normal rhinoceros but with small wings on its back, it had a number of body piercings and Rinnegan, implying it is being controlled by Pain as well as dark marking around its eyes. It also had a giant chakra receiver stuck in its forehead.

Abilities
Because of its sheer size and nature, it had great brute force, able to destroy an entire building after charging into it.

Itachi Pursuit Arc
In the anime, it was first summoned during Pain's fight with Jiraiya, where it charged at Jiraiya, forcing him to jump out of its way. It was stopped by Gamaken.

Invasion of Pain Arc
In the manga, it was first summoned during Pain's attack on Konoha: first to keep Shizune and her ANBU guards from learning Pain's secret and again during his fight with Naruto. Naruto threw it into the air with the strength given to him by Sage Mode, and it was subsequently defeated by Gamaken.

Pains Nashorn