Volume 25 Bonus Chapter (and Extra Illustrations) : r/OnePunchMan

Vol 24 extras (The rest in Vib's post) : r/OnePunchMan

Some extras from volume 26 (Low quality) : r/OnePunchMan

One-Punch Man's Newest Manga Volume Includes Unexpected Extra Chapter

All illustrations and bonus content from volume 26 : r/OnePunchMan

One Punch Man Volume 27 Extras. From @Nan_C_the_H0BBY on Twitter. : r/ OnePunchMan

Magpie's Nest — One-Punch Man Volume 24 Illustrations

One-Punch Man: Hero Association / Characters - TV Tropes

Some extras from volume 26 (Low quality) : r/OnePunchMan

Vol 24 extras (The rest in Vib's post) : r/OnePunchMan

Inside Cover and Back Cover,Bonus Chapter and Extra Illustrations from Volume 26 (Scan/HQ) : r/OnePunchMan

Changes and Redraws in Volume 24; compared to the online releases. There were only 4 since the chapters were already redrawn, description of the changes is under the images. : r/OnePunchMan

Volume 25 Bonus Chapter Translated : r/OnePunchMan

Vol 24 extras (The rest in Vib's post) : r/OnePunchMan

One-Punch Man, Chapter 34 - One-Punch Man Manga Online

One Punch Man Volume 27 Extras. From @Nan_C_the_H0BBY on Twitter. : r/ OnePunchMan