Does anyone know what this is? is it poisonous to humans or dogs.??
No interactions present.
It is quite harmless. The "sting" is in fact an egg-laying tube (ovipositor to the cognoscenti), and only horntails of the female persuasion have them - for laying eggs in softwood.
A really good "spot" - I have looked for this species for years without success.
Lat/Lng: 52.2383, -1.0564
OS grid ref: SP645604