Blocker Skill

I'm creating an AOS and I have a tuskarr hero that can learn the ability to build a giant igloo around himself.

I've got it working up to a point, but I'd really like him to block units from walking right through him, and I don't know what stat in the object editor deals with that.

I've been playing around with it for a while and I think it might have something to do with collision size and AI placement radius, but I can't figure it out. Anyone here run into this before?

BTW, the hero's ability is based on metamorphosis and it turns him into a unit with no movement speed or type, so he just sits still.

maybe base the ability off of mechanical goblin abilty that the tinker has... it will allow the player to deactive it aswell.

Probably the most reliable way would be to convert him to a building with the morph ability, and choose a building pathing map that matches your igloo's size.