Can my library be multiple creatures on the battlefield simultaneously?

If you use Split Screen and multiple Animate Library auras.

If I bounce my library (enchanted withm animate library) to the top ofg my library while yet another aether vortex is out (so it does not technically leave the battlefield) does my library have infinite cards in it now?

You can’t bounce your library to the top of your library. It’s already there essentially.

Hey Mark, I was drafting my Un-Cube last night and my friend asked a question that I had no clue how to answer. What would happen if a library enchanted with Animate Library is given phasing? Would the person who controls the library lose since they go to draw from a library that doesn't exist while it's phased out?

You can draw from a phased out library. Drawing doesn’t define where your library has to be.

RE: "What happens if my library is enchanted with Animate Library and is phased out during my upkeep? The last line of text states that if the enchanted creature would leave the battlefield, you exile the aura instead." - Permanents that phase out don't leave the battlefield

Right, we changed how phasing works. That doesn’t prevent you from drawing off it as a library though. Being phased out doesn’t stop that.

All these animate library questions really showcase why silver bordered/acorn exists, don't they?

Not really. There are a huge number of eternal legal Magic cards that lead to odd interactions, so that’s not really unique to acorn cards.I just don’t tend to answer those kinds of questions on the blog as I’m not the black border Rules Manager.

Re: animate Library without "it's still a library".As far as I understand this is a bit like "colorless is not a color".If you don't have a library, you also don't have an empty library. So you can't lose the game for drawing from an empty library. You can't draw cards at all.Do I understand right?

Not exactly. The inability to draw a card kills you. The game doesn’t care if there’s nowhere to draw it from.

What would happen if Animate Library didn't have the "it's still a library" text?

It wouldn’t function as a library which among other things means you’d lose on your next draw phase.

Un-ruling please! What happens when you split screen an animated library?

Animate Library is an aura, so you would divide your library into four libraries and then animate one of them. Not a great combo.

If I use Animate Library on my library, then I mutate it with the mutation on top (based on what I can see, Animate Library will set the power and toughness, though), what happens when Animate Library leaves the battlefield? Does the mutation fall off? Does the library remain a creature? If it’s still a creature, what happens when it would leave the battlefield?

Here’s what happens. You animate your library with Animate Library. Its power and toughness are equal to the number of cards in your library. You then mutate it putting the mutate creature on top. It retains the power and toughness from the animated library. When it would leave the battlefield, exile Animate Library instead and your library goes back to being a library and the mutate card becomes the top card of your library. You’ll draw it the next time you draw a card.

If I'm playing Unstable against an opponent who has Animate Library out, and I use Spike, Tournament Grinder to bring out Oko, Thief of Crowns and turn their library into an Elk, does that take away the ability to draw from their deck? If so, does that mean they deck out?

You can’t take away the library’s libraryness.