Hint
The rather improbable subject of the pun is penmanship.
Charlie
You just know this, don't you? Even though Hammerhead Shark came out 22 years ago and isn't exactly an important card?
Which country is crossed by the train shown at left?
(Don't give up if you don't recognize it. You can puzzle it out!)
The U. S. has lots of railways called XXX Pacific and lots of stuff with Indian in the name, but I know U. S. trains pretty well and this doesn't look like one (nor did it ring any bells). Canada? Probably not... they don't use the term "Indian" so much. Could it be India? English still has official status there, but "Pacific" doesn't make any sense.
That's when it hit me that the Pacific is an ocean (well, duh)... and so is the Indian. There aren't many countries that border both: just Indonesia, arguably Thailand/Malaysia/East Timor, and *aha* AUSTRALIA!
Solution
This question initially had me baffled. The train is clearly from an English-speaking country, but which one?
Congratulations to yesterday's solvers Inca, Leo S., Yana, Newton, Jessica, Kate, Mr. Gregg, Dr. Yetman, Graham, and Magoo. Thanks to everybody who made a guess!
Ten years later, Dr. Shapiro revived Puzzle of the Day at Proof School, writing each day's puzzle on a name tag. After 600 puzzles or so, he was just starting to feel normal about students reading his chest all the time when campus closed and the puzzle, like the rest of our lives, moved online. New puzzles are posted daily on school days.
Want to catch up on old PotDs? There's an archive currently containing puzzles from March to June 2020.