Squirrel Girl began last year with a major milestone: January 2017 marked the 25th anniversary of her debut in Marvel Super-Heroes #8, in a story by Will Murray and comics legend Steve Ditko. More impressive, that month also marked the two-year anniversary of her first solo series, The Unbeatable Squirrel Girl, a book that remains one of the best -- if not the best -- comics currently published by Marvel or by any other company.

After three years, the creative team of Ryan North, Erica Henderson, Rico Renzi and Travis Lanham continue to craft a book that manages to be equally hilarious, intelligent and heartwarming, all while genuinely appealing to readers of all ages.

RELATED: INTERVIEW: Ryan North on Squirrel Girl’s Journey to the Forbidden Pla-Nut

While The Unbeatable Squirrel Girl was hilariously brilliant from the very beginning -- its first issue famously opened with a parody of the 1960s Spider-Man theme song -- the book continued to excel in 2017, beginning with an anniversary issue, the introduction of a new flying squirrel costume (and a new nemesis to go with it), a battle against Dinosaur Ultron in the Savage Land and a special "zine" issue that was only the second fill-in in three years.

That's right: in three years, Erica Henderson drew 33 issues of Squirrel Girl, plus an original graphic novel, The Unbeatable Squirrel Girl Beats Up the Marvel Universe, a stunning achievement. Even more impressive is that Henderson also managed to squeeze in the first six issues of Archie Comics' Jughead revival within that time, written by Chip Zdarsky.

Henderson's cartoony style is a perfect fit for Squirrel Girl and her pals, and she has honed it over the past several years so that she can perfectly encapsulate exactly what a character is thinking through their facial expressions. Perhaps her most impressive moment: Henderson managed to sell issue #23's Programming Montage gag through the expressions of boredom and frustration on Doreen and Nancy's faces.

And so Doreen and Nancy formed a team and got right to work, which we will now illustrate with... a programming montage!!! Followed by three panels of them writing code and looking bored

Meanwhile, 2017 was the year Ryan North fully embraced his destiny, and brought us not just a Squirrel Girl arc set in the dinosaur-filled Savage Land for, um, very important plot reasons, but also introduced the world to the glory that was Dinosaur Ultron. Dinosaur Ultron was a flash of mad brilliance that could only come from North, who is most famous for his web comic Dinosaur Comics and who holds a masters degree in computer science from the University of Toronto.

Dinosaur Ultron holds Squirrel Girl in its tiny tyrannosaurus hands, while she punches him, to no effect

(Henderson also deserves a shout-out on Dinosaur Ultron, with a design that seamlessly melds the classic Ultron look into the form of a Tyrannosaurus rex. That head is pure Ultron, but also unmistakably T. Rex.)

But most impressive of all was probably the Zine issue, #26, which presented a number of short comics, drawn by an impressive team of guest artists that included Chip Zdarsky, Madeline McGrane, Tom Fowler, Carla Speed McNeil, Michael Cho, Anders Nilsen, Rahzzah and even Jim Davis of Garfield fame. The comics, allegedly written by Squirrel Girl and her pals to raise money for a local library, alternate between the hilarious (Kraven the Hunter's "The True Story of Spider-Man," drawn by Michael Cho, and Spider-Man's response, "Hey Kraven, Squirrel Girl Showed Me Your Comic, So What the Heck," with art by Rahzzah), existential ("Brain Drain's Olde-Tyme Feel-Good Inspiration Corner," with art by Tom Fowler), introspective (the Wolverine comic, drawn by Anders Nilsen) and the silly ("Galactus Gags," drawn by Jim Davis and his assistants Gary Barker and Dan Davis).

Silver Surfer: After a Long Day, I love to visit Television Planet and catch up on my favorite shows. WAIT! What happened to Television Planet? Galactus: TV Dinner (Burp)

My favorite, though, was probably the Loki comic, which reads forwards and backwards, telling a very different story each time, all with fantastic art by Carla Speed McNeil that is laid out in a panel design reminiscent of a chambered nautilus. The issue is a tour-de-force, and was a brilliant way to give Henderson an issue off.

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By leaning hard into their strengths, the Unbeatable Squirrel Girl team have managed to create a book that remains hilarious, insightful, and still groundbreaking after three years; an astounding achievement for a book many did not expect to last a year. It was easily one of the best comics of 2017, and I'm looking forward to reading it into 2018 and beyond.

Keep reading in the coming days for more of CBR’s picks for the Best Comics of 2017.