It’s the part with the brain. It’s also very hard to do when he has his adamantium.
However, it’s worth noting that the adamantium is toxic and his powers don’t work as well while they’re constantly fighting it, meaning non-metal Wolverine has regenerated from clumps of cells that no longer had a brain. This implies his mutation can both rebuild his entire body from scratch and that a brain isn’t necessary either, BUT the largest cluster still probably was the only active one, otherwise we would have had multiple Wolverines growing from the cell clusters that survived brain death, so, to me, the more interesting question is what happens if you eradicate his brain and then cut the remainder perfectly in half?
One must assume it would indeed result in Cloneverines. It’s only logical.
I don’t read comics but some googling says wolverine managed to regrow completely from a single drop of blood so… Yeah…
He also merged with Deadpool for a few minutes after both where turned into soup. https://static1.srcdn.com/wordpress/wp-content/uploads/2022/07/Logan-Deadpool-Gross-Hybrid-in-Wolverine-23.jpg
