Arises from the essence of consciousness of Xavier and Magneto, Onslaught is almost invincible.
His thick armor plates reminds me of a crab and more similarity for this version of Onslaught.
Physically he looks like a mutation of crab and some kind of a bug (lady bird???) and he got a bird like pair of legs.
His face resembles Megatron from the first Transformers Movie to me.
What a dynamic combinations.
Oh, He is a BAF (Build-A-Figure) from the Marvel Legends Onslaught Series 13 produced by ToyBiz in 2006, if you have forgotten.
Note; All pictures are copyrighted by jimho