This refers to the short-lived expansion of
Muppet Babies. Only 3 (out of 18) episodes were aired. Following the cancellation of this part of the show, an MB rerun was added to fill the void left behind by
Little Muppet Monsters.
Here's the MB&M intro (skip to 0:30)
http://www.youtube.com/watch?v=JVkvLJToU0k
The instrumental version of the theme that starts from "We're down in the basement putting on shows" was used as the commonly-heard closing title theme to MB from 1985 on, and the short opening title theme of MB that follows the MB&M title was the common version used for MB in syndication.
The lyrics:
Muppet Babies and Little Monsters, too
Welcome to our house, there’s lots of fun for you!
(
Muppet Babies opening clip)
(Baby Scooter) I like my computer
(Baby Skeeter) I swing through the air
(Baby Rowlf) I play my piano
(Baby Gonzo) I have blue hair, ha!
(Bad trumpet riff)
(Baby Gonzo) Huh?
(Cue commonly-heard Muppet Babies closing credit theme)
We’re down in the basement, putting on shows
Little Muppet Monsters!
Kermit & the Penguins and Pigs in Space, too
Everybody’s joining Tug and Molly and Boo
(Sandwich) This is ridiculous.
Little Muppet Monsters!
Little Muppet Monsters!
Muppet Babies, we make our dreams come true
Muppet Babies, we’ll do the same for you
Muppet (Muppet, Muppet…)
Babies (Babies, Babies…)
And Monsters too! (Bad trumpet riff)
This is then followed by the commonly-seen short version of the MB opening title.
The standalone lyrics to the LMM segment are:
http://www.youtube.com/watch?v=pChZgbqsakQ (video)
They're down in the basement, everybody knows
Little Muppet Monsters!
They built a crazy gizmo, they're putting on a show
Little Muppet Monsters!
Kermit & the Penguins and Pigs in Space, too!
Everybody's joining Tug and Molly and Boo...
(Animal) What?
Little Muppet Monsters!
Little Muppet Monsters!
Little Muppet ... Monsters!
~Ben
~Ben Edge (BigBirdABCDEFGH)