Jonathan mentions The Blob -- a very fine dance indeed, I think. (see below)

A couple of additional things I do with it.

1) Blob up and down (Down and Up?)

Hold hands in small blobs or giant blobs and go down and up with appropriate blobbish sound effects.

2) Blob ALL the Way Around -- do si do as Blobs (When you have at least two lines so you can form two giant blobs) 

Get the blobs circling left and encourage them to go around each other -- kind of like a giant bouquet waltz. Success rates will vary when doing this but it will assuredly create a lot of movement, confusion and laughter, even if everything falls apart.



The Blob
Sherry Nevins?
Longways proper for as many as will
with partners (any age, any gender) facing each other in a long line.
Starting at the top, join hands in groups of 4 or 6; this is your blob.

1 - Long lines forward and back
2 - Forward and back again
3 - Partners right elbow around
4 - Partners left elbow around
5 - Blobs join hands and circle left
6 - Circle right, back to place (top blob keep holding hands, others
jump WAY back from partner)
7-8 Top blob sashay down the center, others clap in time, & move up
towards the top

--
Ridge Kennedy [Exit 145]

When you stumble, make it part of the dance.