https://www.cnet.com/news/fortnite-season-6-is-coming-thursday-heres-what-we-know-so-far/

From the first image we can tell that's definitely a llama, Epic's unofficial mascot for the game, and from the text posted, we know it's now some kind of DJ and it seems to be inside the fabled Fortnite cube. There's a potential this DJ llama could be a new skin. 

The second tweet has the same purple cube background as the first, but this time shows a masked hero that looks like it has some kind of wild west theme. The text -- "Saddle up!" -- might mean horses are being added to Fortnite's small selection of vehicles, but that could be a stretch. Epic will likely post more teasers (that are hopefully less vague) in the next couple of days leading up to the start of season 6, so check back here for more clues daily.