Ultimate Christmas is a symptom combo exclusive to the Santa's Little Helper scenario. When this combo is active, Santa and Rudolph will come out of retirement and pose with children for pictures, making them very happy. It increases infectivity and happiness.
|Symptom Combos in Plague Inc. and Plague Inc: Evolved.|
|Assassin ▪ Bath Time ▪ Blind Genius ▪ Blood in the Air ▪ Boomer ▪ Carpe Jugulum ▪ Cranial Dispersion ▪ Discovery Channel ▪ Fly Magnet ▪ On The Naughty List ▪ Oops ▪ Profuse Bleeding ▪ Projectile Vomiting ▪ Public Defecation ▪ Red Ape Redemption ▪ Red Rain ▪ Rude Awakening ▪ Runner ▪ Spitter ▪ Swine Flu ▪ Tank ▪ Ultimate Christmas ▪ Vampire Bat ▪ Walking Contradiction ▪ Walking Dead ▪ Zombie Panic|