Mobs are following players in mid-air. It happened that Diamond dogs and Timberwolves were hovering to the top of the trees where my friends tried to run away from them.(http://i67.tinypic.com/2mg1e91.jpg)
That is unusual! Thankfully it's something already reported in the helpdesk or LoE discussion I think :)
Gonna go ahead and lock & move this thread for now. Thank you for bringing this to our attention!