When using Pac-Man's Up taunt, the Namco Roulette taunt, random characters from other Namco games will appear: here is the list of characters that appear when using the taunt in each version of the game
Clovis (Dragon Buster)
Don (Taiko no Tatsujin)
Fighter (Bosconian, sound: "Alert! Alert!")
Fighter (Galaga)
Galaxip (Galaxian)
Ghost (Pac-Man)
Gilgamesh (The Tower of Druaga)
King (King & Balloon, sound: "Thank you!")
Mappy (Mappy)
My Car (Rally-X)
Paccet (Baraduke, sound: "I'm your friend!")
Pooka (Dig Dug),
Red Baron (Sky Kid)
Secret Fighter (Gaplus)
Solvalou (Xevious)
Topcup (Libble Rabble)
Andor Genesis (Xevious)
Valkyrie (Valkyrie no Densetsu)
Runner (Metro-Cross)
Clovis (Dragon Buster)
Don (Taiko no Tatsujin)
Fighter (Bosconian, sound: "Alert! Alert!")
Fighter (Galaga)
Galaxip (Galaxian)
Ghost (Pac-Man)
Gilgamesh (The Tower of Druaga)
King (King & Balloon, sound: "Thank you!")
Mappy (Mappy)
My Car (Rally-X)
Paccet (Baraduke, sound: "I'm your friend!")
Pooka (Dig Dug),
Red Baron (Sky Kid)
Secret Fighter (Gaplus)
Solvalou (Xevious)
Topcup (Libble Rabble)
Andor Genesis (Xevious)
Valkyrie (Valkyrie no Densetsu)
Runner (Metro-Cross)