FTFA:

Q: This whole snake thing is just a metaphor, right?

A: I assure you, the snakes are very real.

Yeah, that's great, but what does it actually represent? The writer is doing the usual "wink wink, nudge nudge, know what I mean, get it" thing, but I never did postgrad and I don't get it.

I believe they're alluding to your PhD defense, due to questions like "does my advisor pick the snake?". Your advisor doesn't pick whom you do your defense to, but its not a random choice either.

It represents the type of A/V cable used to connect your laptop to the projector

That is only one of many possible snakes. It was not known to exist in thesis defenses before circa 1995. Since that time it has become a regular foe.

Oh, so THAT's why my projector that I used for my PhD defense didn't display red.

<dijkstra>

Why, did the red elements mean something special?

</dijkstra>

I'm assuming it's the exam team member that wants to torpedo a student to show how smart s/he is by asking something tricky or tangential.

I was lucky. My supervisor asked for recommendations for who to ask from the Math department and I replied "a push-over". He thought for a second then said "Ok, I know who to ask."

My advisor occasionally kept snakes.

He asked the question "What is a random variable?" in an EE qualifying exam (not mine). The correct incantation ("A measurable function into the reals") was not heard from the candidate. A lot of other stuff was heard, at length.

The cure for this particular case of snake bite was a remedial class in measure theory.

Thesis defense, I think.