When it comes to plants, common names can be quite confusing because many plants that are entirely different, from entirely different genera might have the same common names.
Moonflower is one of the common names for Ipomoea alba:
Moonflower (Ipomoea alba)
Moonflower is also one of the common names for
Jimson Weed (Datura innoxia)
They are in two entirely different families of plants and both are toxic to dogs and cats.
Here is the ASPCA page for each, listing the toxicity and symptoms of animals who have ingested these plants:
Ipomoea alba:
https://www.aspca.org/pet-care...
Datura inoxia:
https://www.aspca.org/pet-care...