For the fluff-gurus out there:

Could a Slayer use a hammer instead of an axe?

Well, the GW models are allways equiped with axes (as far as I know, not beeing a dwarf player). But in Warhammer online I believe that the slayers can equip hammers (if I recall correctly) as well as axes and as I've understood it GW are really careful with their license and would probably not allow it unless it was officially ok.

Snorri from the Gotrek and Felix books uses a hammer and an axe. I'd say it would be fine.

I'd say whatever gets the killing done...

Would also be a breath of fresh air to see a slayer using hammers instead!

"I never heard a hammer never getting lodged in someone head, that's why!"

Some of the very old GW Slayer models have swords... so I think hammers will be ok

Thank you very much, everyone! So our Slayer can use his 2-handed Hammer after all, it seems. Great!