I'll give you the hint: the way to destroy this thing is a spell with Target effect that deals not-that-much damage. Jeremy, that's you.
I think I know what spell you mean, but unfortunately at 16th level, I don't yet have a way to counter epic SR.
I think it's SR is 44. A bunny has no CR that I know of, +18 CR for paragon template (unless it is a 7 hd dire bunny

), +16 CR for pseudonatural template = CR 33 for one of the buggers. Unfortunately, the paragon template also grants SR of 10 + CR. As a 16th level cleric I'd have to roll a 28 on my d20 for my caster level check to affect it with a damaging spell. Even if it only has 50 hit points.
So here's hoping reaper can hit it's 87 AC (10 base +3 size +15 dex +12 insight +12 luck +35 natural) because this round, the critter is almost immune to me.

Almost, in that I gave reaper +40 more charisma. As he can normally do all his attacks at +51, if he ceases power attacking, attacks with only his primary to avoid off hand penalties, doesn't use all his gain extra attacks for negatives to attack rolls, he should get up to high enough to hit the thing once, which should be plenty to do it in. Even if it's less than 100 pts. And with the extra +20 from divine shield alone, I don't think hitting will be a problem, though doing less than 100 points of damage might be.
Though I could be missing something.

Still I'm pretty confident that the melee people can solve this one. Though our archer seems a little outclassed. I'll have to change my day of resting to a +48 dex to him to get his attack bonus up a little.

((Toldja! I'm a buffing mad man!

))