It's a slang form, and we recognize it as a couple of words squashed together. "Swag" as in "swagger". A person swaggers (or walks with a swagger) when they have confidence, or at least have a reason to do so. You might find the expression "S/he's got swag", which is fairly positive to say, although it's still slang. "-alicious" as in "delicious". You can understand this as roughly meaning "enjoyably so". It's not standard English of course, so don't be surprised if it falls out of fashion fairly quickly.