Catawiki auctions has the following item up for bids :
Original Art piece by Frank Zappa and Gail Zappa.
Origin of the character used in both Greggery Peccary AND Thing Fish!! Frank did most of the work on it on March 28, 1970 and Gail did hers on October 3, 1971
13 by 8 1/2 inches
Purchased at the Zappa estate auction at Julien's Auctions in Los Angeles.