My nearly 9 month old has become attached to a baby mink blanket. He loves to cuddle it. Is it safe for him to cuddle it in his cot as he goes to sleep or during the night? He is crawling and can roll over on his own.

Red Nose recommends withholding any soft toys or comforters for babies less than 7 months of age, as they may increase the risk of suffocation.
Keep soft toys out of the sleeping environment for babies under seven months of age because they may cover the nose and mouth and interfere with breathing.
The risk posed by suffocation by the presence of soft objects in the baby’s sleeping environment outweighs any benefit to the baby from a soft toy. It is therefore advised not place soft toys and other soft objects in the cot for babies under seven months of age.
Seven month old babies are more likely to explore objects in their sleeping environments than younger babies. Some babies over seven months of age may appreciate a small object such as a soft toy to provide comfort and connection (transitional object1) during times of separation from their parent.
https://rednose.org.au/article/soft-toys-in-the-cot

Red Nose does not recommend any specific products orl types of comforters.
However, it is important not to use one that is large (& may cover baby’s face) or with objects (like beads) attached to it which may become loose or products that have small buttons in them that a child may swallow or choke on.
Also, ensure there are no strings or cords that may wrap around baby’s neck, creating a risk for strangulation.

Red Nose also says:
Keep the cot free of large soft toys, pillows, bumpers, activity centres and anything else that could be ‘stacked’ to assist a young child/toddler to climb out of the cot.
https://rednose.org.au/article/can-my-baby-have-a-soft-toy