What's this pink flower in my lawn? Is it poisonous? I am in the UK
I think it's possibly Lathraea clandestina at the bud stage, although this usually appears in spring rather than autumn - how the flowers develop will confirm or deny this ID. Its common name is purple toothwort, and it's rather uncommon in ordinary gardens, usually appearing near trees or in wooded areas, though you can actually buy it at garden centres. It isn't poisonous, and is usually associated with tree roots; it is considered parasitic because it gets all its nutrients from another plant's woody roots, which is why it doesn't have any leaves, but does not cause damage to any tree its associated with. Further info here https://www.first-nature.com/flowers/lathrea-clandestina.php
If, as it develops, it becomes obvious it is not Lathraea, please post another photograph...
That looks more like a pelleted rat poison. Something like Final Rodenticide.