Pina

Pina is Silica's «Feathery Dragon» and the first known monster to be tamed in Sword Art Online. It understands Silica's commands and will protect her in any way it can, as it is her «Familiar». It is also present in ALfheim Online as her Cait Sith familiar.

Appearance
Pina is a «Feathery Dragon» with its blue body covered in soft, pale blue feathers and two feathers instead of a tail.

The Black Swordsman (Aincrad 35th Floor, February 2024)
Pina became Silica's familiar after Silica fed Pina some peanuts she bought.

After Silica gets into an argument with her party members, she leaves them without even taking recovery items with her. She and Pina get lost in the forest, where at one point they are surrounded by monsters. Pina takes a deadly blow meant for Silica and perishes. Silica and her temporary companion Kirito, go to «The Hill of Memories» on the 47th floor to obtain the rare pet revival item «Flower of Pneuma». After they return to town with the flower, Silica uses it and successfully revives Pina.

ALfheim Online
Pina was included as converted data from SAO.

When Silica joined a party to obtain the legendary sword excaliber from the underground dungeon, Pina is included as a team member to help obtain the legendary sword.

Abilities
Pina is shown to be capable of healing small amount of health, although there's a limit to this.

Pina is shown to possess a greater amount of knowledge and self-awareness than other tamed familiars which allows it to think for itself at times. (Yui said that Pina possesses a complex mind structure)

Pina can give increased jumping capabilities to Silica by gliding momentarily in the air.

Pina can do a special attack by shooting bubbles which paralyzes an enemy opponent.