Free Comic Book Day on May 4 marks the debut of the Savage Avengers, which teams Brother Voodoo and Wolverine with newcomers Elektra, Venom, the Punisher and Conan the Barbarian.

That’s easily the most unexpected lineup since Brian Michael Bendis revamped the team in 2004’s “New Avengers.” It got me thinking about who the unlikeliest members have been in the team’s 56-year history.

The Avengers have always been a mix of top-tier characters and unexpected, story-driven choices. Triathlon and Silverclaw don’t make my list because writer Kurt Busiek confirmed on Twitter that they were created to join the team. I also threw out off-beat additions like Jessica Jones, since co-creator Bendis added her.

10. Quicksilver and Scarlet Witch

They’re classic Avengers now, but the first big roster shakeup in 1965’s “Avengers” #16 left Captain America leading reformed criminal Hawkeye and this duo, who debuted a little over a year earlier in “X-Men” as charter members of the Brotherhood of Evil Mutants.

9. Demolition Man

Not Sylvester Stallone or Wesley Snipes, this superhuman pro wrestler suffered one setback after another working alongside Captain America, who made him an Avenger. He’s been homeless, manipulated by villains and thought dead more than once, but he’s remained a steadfast ally of Captain America and the Falcon.

8. Squirrel Girl

Introduced as a would-be sidekick to Iron Man, Squirrel Girl was plucked from obscurity and inducted into the Great Lakes Avengers (who aren’t considered actual Avengers). With a penchant for defeating almost any villain – as much through mutual understanding as fisticuffs – she joined Sunspot’s post-“Secret Wars” team and was shown leading the Avengers in a flash-forward in her comic.

7. Spider-Man

For years, Spidey was an outsider, frequently assisting other heroes but never joining a team. That changed in the early ’90s, when he officially became a reserve Avenger. “New Avengers” promoted him to a regular.

6. Sandman

The longtime Spider-Man villain was made a reserve Avenger by Cap while trying to put his life of crime behind him. He assisted the team on multiple missions before leaving after a dispute and working alongside Silver Sable’s mercenary group Wild Pack.

5. Nico Minoru

Nico has the sorcery skills and power to be an Avenger, but as a member of the tight-knit Runaways, it was a surprise when she joined the ranks of the all-female team A-Force.

4. Two-Gun Kid

A character from Marvel’s Western comics, attorney Matt Hawk moonlit as a heroic gunfighter in the Wild West and aided the Avengers when a time-travel adventure landed them in the 1870s. He returned to the present with the team and was granted reserve status.

3. Deadpool

Deadpool’s star power and popularity exceed that of many Avengers, but few expected the unstable, reformed villain to make the team. Captain America drafted him for the reformed Unity Squad after a case of mistaken identity gave Deadpool a high profile and deep pockets to support the team.

2. Ghost Rider

With his horror roots, Ghost Rider never seemed an obvious Avenger. I figured if he made the cut, it would be the classic Johnny Blaze or ’90s Danny Ketch version. Instead, newest Spirit of Vengeance Robbie Reyes, who drives a flaming car rather than a motorcycle, joined up in the team’s latest reboot.

1. Wolverine

The Beast was the first character to claim membership in both the X-Men and Avengers. Then Bendis put Wolverine, the most recognizable X-Man, on the New Avengers, despite his reputation as being willing to cross lines Avengers traditionally won’t. Since then, Storm, Cannonball, Havok and Rogue have joined the ranks of Earth’s Mightiest Heroes.

Evan Bevins is the writer of the webcomic “Support Group.”