Yellow-staining mushroom
A poisonous Agaricus that may cause severe gastrointestinal symptoms.
Russula emetica
Русское название: Сыроежка жгучеедкая
A red-capped Russula traditionally associated with gastrointestinal upset after consumption. Many Russula species have similarly coloured caps; colour alone does not establish which species a person found.

Never decide to eat a wild mushroom from a photograph or online description. A mistake can be fatal. For mushroom ingestion or suspected poisoning, contact emergency medical services or a poison centre immediately, even if symptoms have not appeared.
Irish Poisons Centre mushroom safety ↗Europe and northern temperate forests
Coniferous woodland and moist mossy ground
Images and brief descriptions are for learning, not for reliably identifying a specimen. Take particular care with poisonous plants and mushrooms.
Identification is never guaranteed by a photo. Scientific names are used to reduce confusion between local names.