Rhyme Me a Rhyme

After the play-within-the-play, and after the King has departed in a huff, Hamlet is in a very merry mood, convinced he's got his proof that the Ghost was telling the truth.  In kidding around with Horatio, Hamlet lets loose with this little poem:

For thou dost know, O Damon dear,

This realm dismantled was

Of Jove himself; and now reigns here

A very, very -- pajock. (III, ii, 276-279)

"You might have rhymed," pipes in Horatio. 

Here's my question for anyone who'd like to take a stab at it:  What word might Hamlet have used to make the rhyme? 

[The OED defines pajock as "a vain or conceited person; a popinjay."   I myself don't recall seeing the word in any other Shakespeare play.  Some editions of the play use the word peacock instead of pajock.  The passage does not occur in Q1.  The word is rendered paicock in Q2 and Pajocke in F1.]