Sylar from Heroes? He doesn't eat people, he just kind of takes a close look at their brain to understand their ability.
Here they are in order :3
Re:Monster - this is a guess, I haven't read it in like 2/3 years.
That Time I Got Reincarnated as a Slime
BOFURI: I Don't Want to Get Hurt, so I'll Max Out My Defense
Arifureta: From Commonplace to World's Strongest
Kirby
Attack on Titan
Finally the spider: So I’m a Spider, So What?
Some similar ones too, just in case you're looking for this genre:
I Grow Stronger by Eating
Berserk of Gluttony
Guy with the white hair and guns is the MC on Arifureta: From Commonplace to World's Strongest
And the spider is from So I'm a Spider, So What? (I really enjoyed this anime)
Partial list
BOFURI: I Don't Want to Get Hurt, so I'll Max Out My Defense
That Time I Got Reincarnated as a Slime
Attack on Titan
That thing on the left looks like it was drawn by whoever animated the original Digimon show