The Wayback Machine - https://web.archive.org/web/20150329103750/https://dev.twitter.com/overview/general/image-resources

Twitter Brand Resources

The resources are available to support a consistent user experience in applications leveraging Twitter & sites using Web Intents. It is recommended that you store these within your own application. For more information on using these marks, consult our Display Requirements.

Birds

The Twitter brand assets and guidelines page includes high-resolution Twitter birds and Twitter bird display guidelines.

16x1632x3248x48
Twitter bird logo blue 16x16Twitter bird logo blue 32x32Twitter bird logo blue 48x48
Twitter bird logo white 16x16Twitter bird logo white 32x32Twitter bird logo white 48x48

Icons

Tweet ActionDefault StateHover State“On” State
FavoriteTweet favoriteTweet favorite hoverTweet favorite on
ReplyTweet reply iconTweet reply hover—
RetweetRetweet iconRetweet icon hoverRetweet icon on

Sprites

Some developers may prefer to work with PNG-based sprites.

EverythingFavoriteReplyRetweet
Tweet actions combined spriteTweet favorite combined spriteTweet reply combined spriteRetweet icon combined sprite