It's probably just a rock
they use rocks as fake eggs to make them look like a normal couple of penguins while they bum each others beaks off.

I wonder if gay penguins "flipper" each other ?
( Goatworrier had your mum and she was shit, Thu 4 Jun 2009, 16:43, archived)

'bum each other's beaks off'
Ha, LOVE that.
( RR I love you ... in a way, Thu 4 Jun 2009, 16:46, archived)