The Wikipedia say on the subject of ‘Maneke Neko’ that:
The Maneki Neko (???, literally "Beckoning Cat"; also known as Welcoming Cat, Lucky Cat, Money cat or Fortune Cat) is a common Japanese sculpture, often made of porcelain or ceramic, which is believed to give good luck to the owner.
Thats all well and good but they forgot to mention that they can be made of LEGO blocks. Neat!