Gruntilda's Lair is the home of the antagonist of Banjo-Kazooie, Gruntilda (or Grunty). It also houses the portals to each of Grunty's nine worlds. Grunty flees to the top of her lair after kidnapping Tooty. Banjo must enter her lair and collect a multitude of objects, such as Jiggys, Jingoes,and Musical Notes. Jiggy's allow Banjo to solve the puzzles which open the portals to the worlds upon completion. Notes allow Banjo to pass through magically sealed doors if he has a certain amount.
- Mumbo's Mountain (1 Jiggy needed for entry)
- Treasure Trove Cove (2 Jiggys)
- Clanker's Cavern (5 Jiggys)
- Bubblegloop Swamp (7 Jiggys)
- Freezeezy Peak (8 Jiggys)
- Gobi's Valley (9 Jiggys)
- Mad Monster Mansion (10 Jiggys)
- Rusty Bucket Bay (13 Jiggys)
- Click Clock Wood (15 Jiggys)
Throughout Gruntilda's Lair, the theme is repeted ad infinitum though it changes in instrumentation according to nearby levels. (i.e. When you are in the Treasure Trove Cove area, the theme has and accodian playing the melody, giving the song a swashbuckling feel. In Freezeezy Peak, the theme is striped to a music box playing both chords and melody very softly.)
The theme is an adaption of the song "Teddy Bear's Picnic" by John Walter Bratton.