i know that brother bobby can complete the blue room (and mines and the ark in normal mode for that matter), doesn't change the fact that virtually any other attacking baby can do the same, better. it is good only in the no heart-producing challenge due to obvious reasons.
also i now think that BOTH steven and brain worm should be in the trash tier due to their terrible dps for their price. a row of abels outperforms 1 row of steven/worm most of the time, you dont need homing when you can just kill the enemies faster.
bob's brain still doesnt seem to worth the slot. you can just block the enemies with cube of meat, that'll buy you enough time. you only have 4 slots by default, so every baby counts.
i would still bump dry baby at least a tier higher.