Grand Mannikin, Lonchura grandis,
Very rarely seen in dealers but they do show up from time to time,and when they do it takes a lot of pocket money to buy them.
As can be seen they have a massive beak and make good use of it when you catch them up for any reason. Beak size appears to give some indication of sex but this is only really noticeable when you have a true pair together.
Hard to find but a joy to keep.