Sometimes when you travel around the map you encounter an Unidentified Flying Object which past. Very weird huh? But if you seen it carrying different object and fight against it you'll get a PuPu card. Here's how to do it. The locations are also set on the world map.
1. Go to Winhill and explore the greenery surrounding Winhill. Eventually you'll enter a fight and see a UFO fly past.
2. Fly the Ragnarok over to Timber and then hit the beach just to the south of it. Here you'll encounter the UFO carrying a statue head.
3. There's a large sandy area just to the east of the Centra Ruins. Here you'll encounter the UFO for the third time. (You know hen your right place, because there's a portal in the vicinity - only on disc 4)
4. The fourth sighting is near Trabia Garden. Look for a small island just off the coast from it. Here you see the UFO for the fourth time, carrying a large leaf.
5. Once you have encountered the UFO four timeshead over the rocky mountains east of Trabia Garden. There you'll see the UFO. Now you can FIGHT against it. Only a strong needed to destroy it.
6. When you have destroyed the UFO, go to the area where Balamb Garden was standing. There you see PuPu. Fight him. He has only 100 HP, so killing him is no problem, then you'll get an Accelerator. But if you give him 5 elixirs, you'll get the PuPu card! This card is very rare!!