with giants as i am sure you know you role to see what attack they do but if you upgrade to a mutant monstrocity you role again to see if it proforms a special action see the beast of chaos rules for chaos giant.

my problem is if the giant starts to jump up and down assume he stays on his feet and dosenot leap on them last round do you have to role against the the jump up and down reslust to see if he jumps on them or is he assumed to pass the test without throughing himself on his foes like is is assumed to role jump up and down for each turn? i have read through the rules and i cannot find somthing that hints ether way. can anyone shead some light on this matter for me?