Or what if:
1: it could throw itself and bounce off the enemies while slowing them and then respawn and wait a lil bit to throw again
2: it would act like the grape thingys from PvZ2 where it would explode into shards what whould bounce through the field hurting enemies but it would kill itself in the process.
and 3: it could be placed and you, the player/isaac could push it to hurt the enemies
The challenge seems cool btw.