You'll probably have much better luck posting a request for IDs along with pictures (embedding the pictures in the post would help) in the Name That Plant Forum. Here's a link to that forum... Here is a link that might be useful: Name That Plant Forum

Thanks for the IDs people. I managed to find info that might prevent me from killing the poor things. And since you're all so nice, can you please help me identify these two other tall/ short plants? I've had them for a while and they've somehow survived my negligence. This one i found sprouting in another succulent pot i bought a long time ago. Could it be a very slim and tender Euphorbia/ Monadenium ritchiei? It has grown several inches since i replanted it months ago. This might be crested, I'm not so sure. All i know is that it takes a lot of abuse and i love the mushrooming/ brain-like form!

about the only thing that will knock this type of thing back.. is severe repeated drought ... and two large dogs who trample the heck out of it ... that piece will probably root ... in a glass of water .... you could probably propagate a bunch of it.. by filling a flat with media... and laying/sticking a bunch of pieces on top .. and setting it all in shade .... and by fall most will be rooted .. with just a little water now and then ... unless its the one sedum in the universe ... that is somehow foo foo .. lol ... ken

I'm not the greatest at identifying these, but I think the one on the right might be a graptoveria hybrid? The left one has grown without enough light and I can't really tell what it is. If there was white sap coming from either plant on the broken parts, that would be concerning. Euphorbia are toxic and come in many different looks/shapes. Their sap is an irritant. If your son hasn't had any ill effects yet, probably they're okay? Even though many succulents aren't very good to eat, most are not harmful. Hopefully someone else can chime in.