i filled a large area with cake in my ultra flat world using the fill command to make a cake land but the mobs that walked on just got stuck spinning 

the enderman that spawned at night walked on and did get stuck but could teleport away but would walk to the block it teleported from until it teleported far enough to teleport twice then it was fine

the animals with four legs such as wolfs and creepers had more freedom could stop spinning for a sec sometimes allowing them to switch blocks

and a mad wolf was weird it was mad at a sheep  and going sideways to it and turning pressing its face into the sheep but not hurting it until the sheep was  pushed off the cake

the mountable animals such as horses pigs and striders did not spin  but walk forward turn around repeat.