Everyone assumes the Light of Hope was a person, but in fact, at the end of the anime Sailor Moon reveals the Light of Hope resides in everyone, in their hearts while Chaos resides in everyone, in the darkest parts of their minds.
A shady image of a character bathed in pink light appears which has caused rumors that this is the Light of Hope. This is not. Another rumor is that Galaxia's Star Seed is the Light of Hope and this is a rumor that exists in the Sailor Moon anime series and is a rumor the Starlights believe until Sailor Moon reveals the truth about Hope and Chaos.
When Sailor Galaxia sealed Chaos within herself, she feared that it would someday overtake her. She removed her Star Seed and sent it off to the far reaches of the universe, hoping that someone would receive it freely. When it came to Earth, her Star Seed found Usagi Tsukino and took the form of Chibi Chibi in order to be near her.
In the final episode, the Sailor Chibi chibi took a form that appeared very similar to that of Sailor Cosmos in the manga. However, Sailor Cosmos does not exist in the anime. It can be assumed if Usagi Tsukino had taken the offer of allowing the Light of Hope to be her new starseed, this is the form she would have become. Instead, she offered her aid to Sailor Moon in the battle against the Chaos-possessed Galaxia, taking the form of the Sword of Sealing as a means to defeat the powerful Sailor Senshi. The sword was shattered by Dark Sailor Galaxia and it resumed the form of Sailor Chibi Chibi before disappearing.
After Sailor Moon finally triumphed through the power of her own love and the Star Seeds were freed, Chibi Chibi reappeared briefly, before she safely returned the Star Seeds which had been stolen, to their rightful hosts before she reunited with her host, Galaxia.