it's a simple 茶巾絞り. Use 17 gr of 黄身餡 for 中餡, then 17 gr each of white 白あん and green-coloured 白あん (Pandan might work well with the egg!). I also like to add a yellow beak.
Shape あんs into logs, fuse them together, wrap 中餡. Then place it into 茶巾, bill first, green side up. Pinch tail with fingers, then pinch really hard to shape the bill.
Unwrap, then shape the chest.
Ideas: Almond aroma or coconut might work well with 黄身餡-pandan, so those might be worked into the 白あん!