Alex was appointed as a sentry with his brother Ryan in Snowdin Path by his father, to look out for viewers and Cody.
Alex is the "annoying little brother" stereo-type. He will take things from Ryans room, leave traps around the house to test them, and will get easily angered by small things.
Alex looks the same as he does in real life, but now has a helmet, and an armor chest plate. He also has a small dagger.
Alex and Ryan fight all the time, and constantly mess with each other. But its obvious that somewhere in there they care about each other a lot.
Ryan will often disobey Daddy05's orders if he does not want to do them. Wich causes him and his father to get into fights.
Mommy05 and Alex do not interact with one another after the viewer indecent. Before that however, they seemed to have a loving relationship.
Alex and Cody get into fights much more than Cody and Ryan, but Alex and Cody seem to have equal strength.
Alex gets picked on, and sometimes even attacked, by Jake constantly. He begs Ryan for help, but he simply joins Jake in his actions.
Alex and Emma get along a large majority of the time, usually playing video games and watching cartoons together. But like everyone else in the family, they get into fights.
- Sticks (these act just like Papyrus's bones.) (there are blue and orange variants)