Is this a fungus?

Is this a fungus?

Observation - Is this a fungus? - UK and Ireland. Description: This suddenly appeared on the grass by the roadside in both ours and our neighbours patches of lawn. We'd like to know what it is and whether it is a problem of any kind (thinking of children and pets etc).

This suddenly appeared on the grass by the roadside in both ours and our neighbours patches of lawn. We'd like to know what it is and whether it is a problem of any kind (thinking of children and pets etc).