Abieron Suthsay, also known as the Star Poet is a Butterfly Person who travelled the universe.
Suthsay arrived on Earth and was lost and so found Sarah Jane Smith who gave it directions back home to Arcateen 5. In return the Star Poet gave Sarah Jane an Alien Comunicator with which Sarah Jane could contact her for help with her poetry. Maria Jackson saw Sarah Jane with the Star Poet in her garden. This was the first alien she ever saw. (SJA: Invasion of the Bane).
Sarah Jane Smith later told Maria Jackson her name and gives her box which Maria Jackson should only use in an emergency. (SJA: Whatever Happened to Sarah Jane?) Suthsay had also given Sarah Jane a warp star on a chain, with which she threatened to destroy the Dalek's Crucible. (DW: Journey's End)
Behind the Scenes
The name Abieron Suthsay was confirmed in Whatever Happened to Sarah Jane?, when Sarah Jane gives Maria an alien box and tells her it was from Suthsay, whom she saw in her garden. Suthsay also gives Sarah Jane a warp star, which she reveals in Journey's End and says it was from Suthsay.