Davesprite

Alternate Future Dave is the Dave that resulted from a timeline where John was tricked by Terezi Pyrope into being killed by the Denizen. This meant that John could not get Jade into the Medium on time, leaving Dave and Rose as the only two players - and the game was unwinnable.

We first see Alternate Future Dave on the Land of Heat and Clockwork four months into the future, where he discusses the deaths of his friends with Rose. Dave is at a high level managing to defeat challenging enemies with ease and style, as well as having obtained some cool stuff, including the Timetables and the Caledscratch.

He is killed by a Becquerel-prototyped Jack Noir in Act 5 part 2.

Davesprite
Dave Strider's Kernelsprite was prototyped with the remains of the Rambunctious Crow by Jade, much to Dave's distaste. In Alternate Future Dave's timeline, it was second-tier prototyped with Lil Cal, a decision said Dave deeply regretted.

After learning as much as possible about the worlds Future Dave uses his Timetables to travel back to a period right before he prototyped his Sprite for the second time. He stopped John from skipping ahead to the Seventh gate and getting killed by his Denizen. He also prevents present Dave from using Lil Cal to prototype with, instead handing over his inventory cards before jumping into the Kernelsprite. By doing this, he prototypes himself and saves present Dave from having to go through the game with the entirely unhelpful Calsprite, becoming Davesprite in the process.

As a Sprite, he gains access to the game's information, in addition to everything he learned in the future. Although he is supposed to be cagey about the information, he promises to share it all with his present day self, simply because he "doesn't really feel like it". He also retains use of his iShades, as they were the only thing he didn't expel into a huge pile of punch cards before he jumped into the sprite. Davesprite uses orange text while chatting on Pesterchum.

Davesprite may be the most potentially helpful Kernelsprite, being open and direct with Dave, as well as having the knowledge to prevent mistakes the Kids made in his own timeline. For some reason, none of the kids have thought to ask him about anything important. He is also upset when John calls present Dave "Real Dave".

Other than that, Davesprite's personality is just like Dave's, since he is simply a version of him from the future, and he claims he will update Sweet Bro And Hella Jeff while the Dave from the current timeline continues his quest. Any birdlike traits are as of yet unknown. He also has arms and fists, though none appear on his sprite like the rest of the other kids' armless demeanor.

After Dave steals caledfwlch from a Crocodile Temple, Davesprite reveals he did the same in the alternate timeline. He defends Dave from a horde of Giclopses after Vriska mind controls him into falling asleep, then uses Dave's pendant to release himself in the same way Rose released Jaspersprite.

He then goes to track down Bro, and finds him in a duel with Jack Noir on the Land of Wind and Shade. He joins the fight and attacks Noir. During the fight, Jade enters the medium, resulting in Jack being prototyped with Becquerel, and killing Bro and Davesprite. His only remains are a pile of orange feathers and his pendant. According to Andrew, this was indeed as a result of returning from an alternate timeline, so the prototyping did not negate his fate.

John's birthday letter to Dave mentioned that Dave ought to get out of Bro's shadow and spread his wings. Circumstances being what they are, feel free to groan.