Among the rarest occurrences on GPX+ are the header events, small sprites that will appear in the header area alongside the party count and current weather. These events manifest as small sprites that, when clicked, will produce a special egg in the user's party or an item in their inventory. Currently, GPX+ implements six header events: the Tiny Egg, the Old Man, one of a number of Chests, the Shady Salesman, the Prankster, and the Strange Portal. Each of these icons will appear on the right-hand side of the header, and will remain across all pages (Berry Feeder excluded) as long as their summoning conditions persist, as described below. Note, another header event can still override the current header event if it has not been obtained.
The Chest icons are recolours of the Wonder Chests that can be found in Pokémon Mystery Dungeon Explorers of Time/Darkness/Sky. Regardless of the state of the user's party, one of five chests has a low probability of appearing in the header icon space. When clicked, the Red, Blue, Gold, and Silver chests can each produce one of three different Summoning Items in the user's inventory. The Black Chest will always produce a Corruption Orb.
Shady SalesmanEditSlowpokeTail for 200,000 points. Having 5 SlowpokeTails in the inventory will award the achievement Slowpoke Tail Connoisseur.
The Shady Salesman can appear at any time while using the site (with the exception of using the Berry Feeder), where the user may purchase a SlowpokeTail regardless of party count. A user does not need to deposit any Pokémon or hatch/release an egg to obtain it, as the Shady Salesman will stay until you either accept his offer or reject it.
PranksterEditKorechu egg will appear in the user's party. If the user chooses not to look, he will tell them they are no fun, and nothing is obtained.
Interacting with a Header Event for the first time will unlock the "Lucky" achievement. Further, obtaining, and keeping, at least five MissingNo. eggs from clicking on the Old Man will unlock the "Getting Kinda Creepy..." achievement, using the same icon as the Old Man.