Marvel decided to depict some of their well-known heroes in animal form on a series of variant covers, so Chris Samnee chose to draw the Silver Surfer as a giant sloth for this variant. Also, note the Watcher as a frog.
Credits appear on final page of main story.
Letters from Andrew E. Plotkin, Fee McBee, Randy Z. Ocha, Benjamin, Wilfredo, Ron Cacace, Ex5150, Balder the Brave, Kenny Mnemonic, Jiximi.