It is a hedgehog
The molehog
Karen Disher has: Played Sally in "Daria" in 1997. Played herself in "Falling for Scratte" in 2009. Played Scratte in "Ice Age: Dawn of the Dinosaurs" in 2009. Played Mother Bird in "Rio" in 2011. Played Molehog in "Ice Age: A Mammoth Christmas" in 2011. Played herself in "The Real Rio" in 2011. Played Scratte in "Ice Age: Continental Drift" in 2012.
The cast of Surviving Sid - 2008 includes: Shane Baumel as Whiny Beaver Boy Paul Butcher as Smarty Pants Molehog Boy Khamani Griffin as Beaver Son John Hawkinson as Beaver Dad Maria Lark as Aardvark Girl Cindy John Leguizamo as Sid Sean Michael Cunningham as Glyptodon Boy Emily Osment as Start Girl Claire Chris Wedge as Scrat
Not sure but it looks like it. There is a scene near the end of the film when the badger pirate Gupta tosses the knife to the molehog, to me... I think it is. The most likely answer is that the animators just recycled it for a particular reason. Not really sure why though.
Manny:Mammoth, very fatherly and protective of his daughter, stubborn(according to ellie)! Ellie: Manny's mammoth wife who is also half opossom( she grew up with opposums)! Peaches: manny and ellie's teenage mammoth daughter, who is also half opossom, high strong and stubborn like her father, likes ethan, wants to be like the girls he hangs around with! Lewis: peaches molehog friend who is there for her even when she isnt for him because he secretly loves her! Diego: saber toothed tiger manny's friend and part of his herd, falls in love with shira! Shira: saber toothed tiger, first mate pirate to captin gutt till he leaves her behind and she joins manny and the gang, falls in love with diego! Captin gutt: pirate ape that captures manny qnd his friend so they destroy his boat he gets mad and swears his revenge! Sid: sloth his family abandoned him a long time ago soo hes with manny and the gang, likes chewed up food , considered screw up, most of the time he is a the glass is half full kind of sloth! Granny: 80 year old sloth, sids grandma, has a pet whale. Named precious! Scrat: sabre toothe squirrel, loves nuts , causes the world to split! Crash and eddie : opposom unkles of peaches, stupid , just live. To have fun!
Paul Butcher has: Played Child in "Kaze no tani no Naushika" in 1984. Played Kanta in "Tonari no Totoro" in 1988. Played Eddie Cown in "NYPD Blue" in 1993. Played Paul Dressler in "ER" in 1994. Played Kenny in "King of the Hill" in 1997. Played Caleb in "King of the Hill" in 1997. Played Kenny in "The King of Queens" in 1998. Played Child in "The Parkers" in 1999. Played Boy in "Providence" in 1999. Played 5-Year-Old Boy in "Six Feet Under" in 2001. Played Kid in "Three Sisters" in 2001. Played Sneezing Boy in "The Bernie Mac Show" in 2001. Played Alex Rosen in "Without a Trace" in 2002. Played Brian Spivak in "The Santa Trap" in 2002. Played Boy in Park in "Power Rangers Wild Force" in 2002. Played Young Michael in "Landspeed" in 2002. Played Charlie in "A Minute with Stan Hooper" in 2003. Played Gus in "Miracles" in 2003. Played Van Family Son in "Hollywood Homicide" in 2003. Played Tim Wayne in "Medical Investigation" in 2004. Played Spencer DeWitt in "LAX" in 2004. Played Jeffrey Barton in "Criminal Minds" in 2005. Played Shawn Cook in "Bones" in 2005. Played The Kid in "Reeker" in 2005. Played himself in "All That 10th Anniversary Reunion Special" in 2005. Played Additional Voices in "Avatar: The Last Airbender" in 2005. Performed in "Kingdom Hearts II" in 2005. Played Dustin Brooks in "Zoey 101" in 2005. Played Chick in "Barnyard" in 2006. Played Kyle Morris in "Holly Hobbie and Friends: Christmas Wishes" in 2006. Played Dustin Brooks in "Zoey 101: Spring Break-Up" in 2006. Played Skeeter in "Over the Hedge" in 2006. Performed in "Ice Age: The Meltdown" in 2006. Played Stanley in "Meet the Robinsons" in 2007. Played Foster in "Tinseltown" in 2007. Played Kyle Morris in "Holly Hobbie and Friends: Best Friends Forever" in 2007. Played Well Dressed Kid in "Back to You" in 2007. Played Kyle Morris in "Holly Hobbie and Friends: Secret Adventures" in 2007. Played Smarty Pants Molehog Boy in "Surviving Sid" in 2008. Played Billy in "The Legacy" in 2010. Played himself in "My Neighbor Totoro: The Totoro Experience" in 2010. Played Jeff Pookie in "MyMusic" in 2012. Played Sean in "Mom and Dad Undergrads" in 2013.