Good evening, Mark. I would like to invoke the sacred rite of birthday trivia! I've heard of the pro-tour in which Unglued, the first un-set, was being played, and a player attacked with Hurloon Wrangler, which has denimwalk (This creature can’t be blocked as long as defending player is wearing denim.). In response, the opponent declared "I take off my pants." However, it's hard to find firsthand accounts of this. Can you tell us how it happened?

It wasn’t at a Pro Tour. It was at 1998’s GenCon. Unglued’s only prerelease events were held at GenCon. That was the event that I head judged dressed as a chicken. We had just started the first round of the first flight and I was walking through the playing area. I then hear the following exchange.“I attack with Hurloon Wrangler.” “In response to you choosing your attackers, I remove my pants.”I literally said, “What have I done?”Happy Birthday!

With the Hurloon Wrangler talk: is underwear a hidden zone? If I'm wearing denim underwear under khakis, an I obligated to inform my opponent that their Wrangler is unblockable?

You must inform your opponent that the Hurloon Wrangler is unblockable. You are not forced to specify why.

Is the thing from your teaser that has never been removed before clothing? Is disrobing scepter finally seeing print?

You’ve never played against Hurloon Wrangler. : )

Hey Maro, as the official un-rules judge I really need to know. Which action is faster, a spell cast with split second, or removing your jeans (in response to hurloon wrangler)?

Neither is faster as that isn’t how the rules work. Taking off your pants is neither a spell or an activated ability, so you can do it in response to a split second spell being cast. As always, local laws (and rules of the game store) must be followed.

Will we ever see a plane with denim pants?

Hurloon Wrangler was from somewhere (in the Un-iverse).

Are all the Unstable cards that care about physical actions designed to avoid incentivizing making others uncomfortable? (I.e.: are they designed to avoid issues like the one with Hurloon Wrangler?)

No Unstable card will encourage you to take off your pants.

Can I throw my denim jacket around my opponent and declare an attack with Hurloon Wrangler before he has a chance to take it off? If no, what counts as "wearing" denim, and at what point during the declare attackers step does said denim have to be worn?

The black border Rules Manager doesn’t get to say things like “You can’t dress your opponent against their will.”

If you Mindslaver your opponent in an un-game, can you force them to undress, given that Hurloon Wrangler makes clothes a part of the un-game?

Nope.

Re: Unsets and things that are indecent, I cannot help but remember the legendary story of the Hurloon Wrangler and denimwalk.

For those unaware, the card Hurloon Wrangler from Unglued had denimwalk, the opponent couldn’t block it if they were wearing denim. At the Unglued prerelease, I heard the following: “In response to your declaration of attack, I remove my pants.” It was then I realized I had a made a huge mistake. : )

Be careful with Un-rules questions! For instance, in the classic "Hurloon Wrangler-Pants Removal" ruling, this could have unforeseen consequences. Mindslaver comes to mind...

There is a meta-rule that local law supersedes any rules. : )