What happened to Gyro? In Episode 80 of the 2011 anime, they showed Gyro's back story then a clawed up chair.  Was he killed or was he eaten?  It wasn't clear what happened to him.
Gyro is killed and eaten after the Chimera Ants invade NGL. 


   but he is later reborn as a Chimera Ant... and the first to keep all of his human memories and break free of the Chimera Ant Queen's control.


Additionally,


   The Chimera Ant King, Mereum, cannot be Gyro, because Gyro was shown leaving the hive at the same time that Gon was training to defeat Knuckle, in Chapter 204, before Mereum was born.