This is a wrecking ball accessory for the Combiner Wars Gravedigger custom concept. The ball opens up into 4 grappling claws radiating from a central base via c-clips, and the assembly can be mounted on any compatible 5mm port using its 5mm peg.
This model has been successfully printed in Purple Strong Flexible Polished.
TFW2005.com thread here.
Flickr gallery here.