I just saw these online, and I think they could be wicked for Lizardmen hero/lord conversions, and thankfully they are 28mm heroic scale. I particularly like the middle one in the image. They kind of remind me of the weapons from the video game Monster Hunter. They are made by a group called Maxmini. I think I shall try these out and hopefully post up the conversion within the next month or so!
I was also thinking about swapping the blades from these to the end of some Krox great weapons. Could make for a unique and brutal look, like giant biological halberds.