is a sleek, muscular, thick-furred, reddish-brown tom with amber eyes. He is born to Rainflower
during a thunderstorm that flooded the camp
. His brother, Stormkit
, is his only littermate, though he is half-brothers with an unnamed kit
About a moon later, Oakkit and Stormkit venture out of the RiverClan camp and run into Goosefeather. The siblings flee from the ThunderClan medicine cat, but Stormkit shatters his jaw. After this, Oakkit is seen to be supportive of his brother through his recovery and renaming to Crookedkit, despite their mother's obvious favoritism toward her uninjured son. Oakkit is made an apprentice, Oakpaw, during this time and his mentor is his father, Shellheart, as requested by Rainflower.
Oakpaw is made a warrior after saving a patrol from a dog. Rather unusually for a young warrior, he addresses all four of the Clans at a Gathering soon after, and is given Loudpaw as an apprentice a little while after. He meets Bluefur at Sunningrocks eventually, and the two have a brief affair, meeting for one night at Fourtrees before breaking off their relationship. Bluefur soon gives birth to their kits, Mosskit, Mistykit, and Stonekit. At first, Bluefur chooses to raise the half-Clan kits as ThunderClan, but due to the rising threat that Thistleclaw was posing to her Clan, Bluefur brings the three kits to RiverClan, although Mosskit dies on the journey. Oakheart tells his then-leader brother, Crookedstar, that he had found the kits abandoned by a rogue, but the tom soon learns their true heritage.
Although Crookedstar and Oakheart had often promised as kits that whoever was made leader would choose the other as deputy, he was not made deputy of RiverClan until after Crookedstar's first deputy, Timberfur. By this time, however, Oakheart had mostly lost the ambition to become leader he had had as a kit.
Oakheart dies right before Rusty's arrival to the Clans, being killed by a rockslide in a battle with ThunderClan over Sunningrocks while fighting the ThunderClan deputy, Redtail. However, Tigerclaw claims to have killed him in revenge for the death of Redtail to cover up his murder of the ThunderClan deputy. He posthumously becomes a driving force in Fireheart's struggle to out Tigerclaw's actions, which eventually leads to Bluestar revealing that she had been his mate.
He makes several appearances in StarClan, including being the one to chose Feathertail as the RiverClan representative on the journey to find midnight. He also gives his daughter, Mistystar, a life of courage to follow her heart in her leadership ceremony.