Maybe the mouse? 
See: 
http://www.phaidros.com/DIGITALIS/englisch/sqk/sqk00100.htm

Obvious obvious. (?;->)  Nerds associate... 

Iannis Zannos
SIM
Tiergartenstr. 1, 
D-10785 Berlin, Germany
Fax: +49 30 25481172

----------
>From: "John-Reed Maffeo" <rlpa80 at email.sps.mot.com>
>To: squeak at cs.uiuc.edu
>Subject: Newbie Question: Where did the name Squeak come from?
>Date: Thu, 18 Feb 1999 7:13 PM
>

>A recent article that I read on the web referred to Squeak and inferred
>that the name had somehow evolved as a function of the close
>association of Squeak Central with WDI.
>
>I know that the name Squeak pre-dates the Disney connection because
>it was in use back in the Apple days circa 1.16. So there has to 
>be another story behind the name.
>
>Would someone kindly relate the story of how the name Squeak came
>to be applied to this interesting dialect of Smalltalk? If not
>I will have to make one up along the lines of:
>
>Smalltalk
>Q ...
>U ...
>E ...
>Alan
>Kay
>
>John-Reed Maffeo
>Mesa, AZ
>
>