What do you call this kitchen appliance?
It is to make banana with milk. I would appreciate if you give me a link of how to use it too :)
Looks like it may be missing the end piece, but if it is what I think it is, you can call it either a "wand mixer" or an "immersion blender." (because you immerse it in the thing you're blending) See these Google results
It's used as an alternative to a regular "mixer" which has a separate bowl & different kinds of beater you can attach (for mixing dough for cakes, bread, etc) ... Or as an alternative to a regular "blender" which you use to make mixed drinks like margaritas :)
...By the way, "stuff" refers to something plural - you should instead ask "what do you call this [thing]?"