Alpacaman

Alpacaman is a so-called uglycute character that appears in its own video game series. The only known video game thus far is the popular video game Alpacaman 2 released in the year 2000, a virtual pet video game where you speak to Alpacaman via a microphone to which he is supposed to respond. Rintaro Okabe mentions that this video game cost him 500 yen and that headphones were included with the game.

On one of the worldlines that appears in Linear Bounded Phenogram, Rintaro Okabe tries helping others dressed up as Alpacaman.

Trivia

 * This game is likely a parody of the Sega Dreamcast video game Seaman.