Probably it's the Platinum Kanohi Avohkii. Also the Golden Kanohi Hau (14 karats) is very rare. Other rare masks are:
I think the most rare BIONICLE set is The Sand Tarakva. It's only a prototype, and there are only 5 of them. Also the rare Kanohi (like the misrpints from 2001, and other special masks) and the old sets from 2001 are very rare.
well,they're found in the 2002 krana packs,which contained 3 krana(bohrok colored),and 2 kanohi(1 gold and 1 silver),so you probably have a 1:6 chance to get it.Basicly(spelling?),it's as rare as the other gold and silver masks in the krana packs.
Bio-codes aren't rare. You can find them at almost any BIONICLE set.
There are no 'pet masks' in Pet Party. However, there are few rare masquerade masks in gift boxes, and sometimes there are masks in the clothing store.
some of the masks are rare it will say if they are rares under the picture
yes!
The color ranges between light and dark golden also rare Golden's are white
Yes, golden tigers are very real animals. They are very rare in the wild.
Golden Arceus
The Golden Seed is an item that you can find in the rare Golden Chamber. The Golden Chamber can only be accessed during special rescue job requests from random clients.
In Pokemon Mystery Dungeon: Explorers of Darkness, the Golden Apple is a rare item you can find in Treasure Hunts. It is also an item you can find in the Golden Chamber which is a rare area to find in dungeons.
This answer is hard to say, but mostly they are not.