The Doctor's cot was the cot in which the First Doctor slept during infancy. It had writing in Gallifreyan carved into the sides, the meaning of which was never made clear. He still had it stored within the TARDIS during his eleventh incarnation, indicating he was sentimental about it.
He put the Ganger-infant Melody Pond in it to rest after he had rescued her on Demon's Run. Upon seeing the cot, Amy Pond pointed out "the Doctor's first stars" hanging above the cot. (DW: A Good Man Goes to War)
He later retrieved it from Demons Run during his search for Melody Pond and kept the cot in the TARDIS drawing room. (VG: The Gunpowder Plot)
Trivia
- It is unknown if the Doctor had a child of his own or if the cot was used after him. However, Alex Kingston raised the question in River Song Confidential: A Good Man Goes to War about "how many babies have really been in that cot?"