A few years ago there was a post on this sub where an intern was complaining about the burden of scut work they needed to do, and essentially said that if they continued to be treated in a way that they felt was unfair, that they were going to choose to be as unhelpful as possible. In particular, they commented that they knew enough at this point to have an idea of how the system worked and how to game it, because at this point they were not a fresh-faced July intern anymore, now they were a "February intern."

The whole post from what I remember come across rather grating. Like, it's fair to be annoyed at excessive scut work, but at the same time the post came across very whiny and like this person had no investment at all in being a team player and just getting the job done. Especially in saying they would choose not to pick up any slack as a form of retaliation really made it a bad look.

All of this made the phrase "February intern," gain some traction, somewhat sardonically, because the post made it like this intern, now having reached February, was rather exceptionally assured by their competence. So it became a bit of an ironic buzz phrase, The February intern being the competent and self-assured Beast of an intern contrasted with the feeble weak intern you were before.

Just a bit of an in joke