If you were to have a frog tied to a lead on a fence and hold a slimeball, it will not follow you around unlike other animals, but it does face you. I did this with a pig and a sheep and a plethora of other animals and they follow you while holding their tempted item. This also seems to be the case for other actions as well like if you bred up frogs. They don't always meet together and can breed from a distance and they also don't pathfind into the water to lay frogspawn. This is compared to other animals that still perform like normal while on a lead.