It Came From Tumblr 2: Electric Boogaloo

From top to bottom...

Leftmost column: Humanish-looking Zero wearing human clothing, Prototype fan character, Boo Mario, Mega Man X, the same Prototype fan character
Middle column: Samantha Carter with some blue jello, crappy doodle of Chie and Yukiko, Malchut from "The Epic of Zektbach" (some Beatmania-related thing), James Heller with a Brawler that looks like a Trapinch because I can't draw feral zombie monsters
Right column: Chibi Alex Mercer and Replicator Carter, some sort of humanoid alien thing I made up, Zero as he appears in Mega Man Zero (YES I KNOW I GOT THE HELMET WRONG), an elf

And then there's Axl sorta hanging out in the upper right corner

X, Zero, Axl (Mega Man X) (c) Capcom
Zero (Mega Man Zero) (c) Capcom, Inti Creates
Boo Mario (Super Mario Galaxy) (c) Nintendo
Samantha Carter, Replicator Carter (Stargate SG-1) (c) SyFy, MGM Television
Alex Mercer, Sgt. James Heller (Prototype, Prototype 2) (c) Activision, Radical Entertainment
Chie Satonaka, Yukiko Amagi (Shin Megami Tensei: Persona 4) (c) Atlus
Malchut (The Epic of Zektbach, Beatmania IIDX) (c) Konami, Bemani

The humanish-looking guy and elf are mine.