Battle masks should've been a feature of all the movie figures right from the start instead of the Mechalive and what not. Hopefully they'll do similar to AOE with figures that have features connected with their onscreen designs, weapons etc.

 

Is there any point to Megatron's horns? Or are those just there for the same reasons every Decepticon in these movies looks so ugly?

 

So he looks like a dark knight and those horns slide down to become his battle mask thus giving him his tusks

 

So his alt mode is a mammoth now?

I've never heard of a knight helmet with tusks.

 

Not medieval European knights as such, but it has been a feature of barbarian warriors, in fiction and media at least.

 

Have you seen the concept art at all? Just look up TF5 Megatron Concept art and you'll see how the horns become tusks in his battle mask mode.