Chuck

Yellow Birds (also known as Speedy Birds and Dasher Birds) are a type of Bird introduced near the end of World 1 in Theme 1-16. The birds are yellow colored (hence their name) and are triangular in shape. Their ability allows them to dash into pigs and structures, making them able to inflict more damage on buildings than the Red Bird. Much like many of the other birds, it's strength usually varies depending on what block is struck and what angle it is struck, but in most cases, it can go through several thin wood blocks. Strangely, they are weak against Glass, despite glass having a much weaker strength then wood.