[tristantio]

Originally Weighted Axe was Tiny until well after Velious (per patchnote):

Changed the size of the Weighted Axe from Tiny to Large (after all, it's a big two-handed axe...). 
If you have one in a bag now, be aware that it probably won't fit back into 
that bag again once you take it out.

http://www.tski.co.jp/baldio/patch/20010417a.html

Edit: Also Hammer of Flattening:

The Hammer of Flattening has been changed from tiny to large. 
This might cause you a little reorganization in your inventory.

http://www.tski.co.jp/baldio/patch/20010508.html

Edit: As well as Giant Tree FLayer:

The Giant Tree Flayer is now Large instead of Tiny.

http://www.tski.co.jp/baldio/patch/20010815.html

Also - weighted axe still isn't working on pets (let me know if I should link to my old bug thread on this).