While Dumbledore is the only Chocolate Frog card we (as readers) get to read, Harry quickly accumulates more cards. On the train ride alone, he gets Morgana, Hengist of Woodcroft, Alberic Grunnion, Circe, Paracelsus, Merlin, and the druidess Cliodna. Morgana, Merlin, and Circe are recognizable names from myth and legend, but the rest are not familiar to me. 

Paracelsus I originally thought might be a strange spelling of Perseus (of Medusa fame), but when I did a quick google search I found this: Paracelsus (1493/1494 – 24 September 1541), born Theophrastus von Hohenheim (full name Philippus Aureolus Theophrastus Bombastus von Hohenheim), was a Swiss physician, an alchemist, a lay theologian, and a philosopher of the German Renaissance. He was not considered a cosmographer, a mathematician, or an astronomer. He was a pioneer in several aspects of the “medical revolution” of the Renaissance, emphasizing the value of observation in combination with received wisdom. He is credited as the “father of toxicology”. Paracelsus also had a substantial impact as a prophet or diviner, his “Prognostications” being studied by Rosicrucians in the 1600s. Paracelsianism is the early modern medical movement inspired by the study of his works. https://en.wikipedia.org/wiki/Paracelsus

Cliodna is technically a made up person for the books, and her bio can be found here: https://harrypotter.fandom.com/wiki/Cliodna. Per her character background, she is (likely) based off of Clíodhna of Irish myth, https://en.wikipedia.org/wiki/Cl%C3%ADodhna. Hengist of Woodcroft is credited (per the Harry Potter Wiki, https://harrypotter.fandom.com/wiki/Hengist_of_Woodcroft) as the founder of the village of Hogsmeade, which is near to Hogwatrs and where the students sometimes go on the weekends, if they are old enough and have permission. This is the only Chocolate Frog character Harry gets on the train who has no identity outside of the book. The other character mentioned on the train ride (only by his famous every flavor beans) is Bertie Bott (https://harrypotter.fandom.com/wiki/Bertie_Bott), who also only exists within the books.

After the snack break, Harry and Ron meet Neville and Hermione, although they don’t introduce themselves right away, and Neville never does. Ron informs Harry that his whole family is and always had been in Gryffindor House, and upon being questioned by Harry reveals that Voldemort was in Slytherin House. More importantly for our breadcrumb trail as readers, Gringotts was broken into – and nothing was taken and no one was caught. The “you-know-what” in vault “you-know-which”.

Of course, Draco Molfoy can’t keep his nose out of anything and everything if he tries, so of course he shows up to introduce himself, along with his “bodyguards” Crabbe and Goyle. Draco, Crabbe, and Goyle try to intimidate Harry into siding with them over Ron and Hagrid, which is the stupidest thing they could do, but eleven year olds are not the wisest people in the world. Scabbers somehow, for some reason, lunges for Goyle and bites his finger, causing the trio to run off. Knowing what we know about Scabbers down the line in the series, I wonder why on earth he would have attacked Goyle (or Crabb or Malfoy, for that matter). 

The train arrives at Hogwarts, everyone is changed, and Hagrid calls the First Years students to the magic boats – Harry, Ron, Hermione, and Neville all end up in a boat together. And thus everyone arrives at the castle.