I don't think getting data from Websites with Snap! will work out well with the Snap! Development Team. Using JS in general to collect data from other websites and stuff is either frowned upon or downright forbidden, depending on what data you're collecting and how bad the data is.
For example, yes, you can collect data from Snap! to get, say, the user's username. But if you were smart enough but pretty dumb and you collected data from, I don't know, Facebook, and you collected the DOB for every user on Facebook, then that's pretty...yeah. It's bad.
From the sound of what you said, I think you assumed that MQTT is basically Cloud. Yes, MQTT can be used for Multiplayer, but it's not the best for making Multiplayer Games...
It is, in fact, a Gaster Blaster on top of Temmie's face on Toriel's body, all under some sunglasses. I made it on Scratch with an Undertale pfp maker of some kind a while back, then, more recently, I created an SVG that looks like it, which is my profile picture right now.