I currently do not have a RoboVac, but have been in the market for one for some time. Every time I go to make a purchase for one, I cannot due to having to buy something else and something else for the kids, because as we all know, they come first over yourself. So I just use a Shark Ion and my Eufy HomeVac.
I can definitely see my 16 month old trying to ride or sit on it. She is into everything and this will be just another thing to fascinate her. She already gets mad when I do not let her use the HomeVac while I am using it, so I bring her in front of it and balance it for her while she pushes. I am super curious to see how she reacts to it. That is why i want to put some googly eyes on it to make her giggle when she sees it.
My dog on the other hand.... he is not afraid of a vacuum that is turned off and can tolerate when I make him lay down to vacuum him off (in no way do I do this against his will, he actually enjoys it), but if I am moving the vacuum around he panics.
I would not run it while I am not home for that reason. Even though I have a camera in my living room to watch him, I do not trust him around it without me present. But he will be curious about it nonetheless.