Tonky

Tonkii is a Beast-type Evil-God class monster who Kirito saves in Jötunheimr. Later, it forms a friendship with Kirito and Leafa, which turns it into an NPC, and allows them to ride on its back.

ALfheim Online
The first thing that Kirito and Leafa notice after dropping into Jötunheimr is two evil-god monsters fighting from a distance. It was clear that the Beast-type evil god (Tonkii) was losing against the humanoid-type evil god. With Leafa's encouragement, Kirito decided to help the beast by drawing the humanoid-type god into the water. The beast-type looked like a mix between a jellyfish and an elephant so Kirito assumed that it had a affinity for water. After defeating the human-type evil god, the beast-type evil god lifted Kirito and Leafa onto its back and traveled to the center of Jötunheimr. While traveling, Kirito decided to name it Tonkii, named after a childhood book that he read when he was younger. After arriving, Tonkii went into hibernation mode and quickly recovered its health points. Kirito and Leafa got off of its back but aided it when it was attacked by a player party. Reaching a low level of health, Tonkii awakens and transforms into a flying beast. Kirito and Leafa successfully scattered the remaining players and Tonkii lifted the two up onto its back and flew to the top of Jötunheimr. Leaving them in a staircase which took them to Aarun through a secret passage.

Caliber
In an attempt to retrieve Excaliber, Kirito leads a group through Jötunheimr. They ride on Tonkii's back to get to the location to begin the quest.

After obtaining the sword, Tonkii saves the group when they are falling from the top of Jötunheimr into what seemed like a bottomless hole.

Tonkii