Poseidon's Chariot

Towards the End of the Battle when all seemed lost Poseidon arrived in his chariot with a number of Cyclops as well as Briares. This gave the Olympians renewed spirit and as the Cyclops began binding Typhon the Olympians attacked again and sent him to Tartarus via a special tunnel Poseidon made just for Typhon.

What Pulled the Chariot
Massive hippocampi.

What the chariot looked like
The chariot is not described in detail other than being very large. It is most likely Green or Blue.