Hey hey!
Other than has already been mentioned above but I couldn’t find any specific websites listing poisonous plants in the Netherlands.
This is what I found when it comes to taxus poisoning:
Symptoms initially expected after ingestion are dizziness, mydriasis, nausea, vomiting, abdominal pain, tachycardia and convulsions, followed by bradycardia, paralysis, diastolic cardiac standstill and death. There are no antidotes nor specific therapy.
And when it comes to the cheese plant:
All Monstera species and their plant parts are toxic to dogs, cats, and humans. While it has edible fruit, the unripe fruit is still toxic. The main toxic agent present in the plant is needle-like, insoluble calcium oxalate crystals. The sap of the plant is dangerous, especially for pets and children, as it can cause irritation and inflammation of the mouth, throat, eyes, and digestive tract.