Pooby more or less acts as Marisa's pet. While investigating some recently discovered ruins, Marisa found Pooby in a secret cache where a high quality rune-lens was hidden. No-one knows how the strange creature ended up in the cache.
Pooby is a lethargic creature, who most often just stays perched on Marisa's shoulder and does little else. On rare occassions, it will chitter into her ear. Generally, that means one of two things: danger is approaching, or Pooby is hungry.