lets see what I can think of off the top of my head
If your child uses it- pacifiers times several. You do not want to be in a stressful situation and be without one- it will greatly add to your own stress.
Formula-The best solution is to breast feed if this is an option. You always have safe formula readily available at the correct temperature. However everyone is not able to successfully BF. In that case, I would pack the ready made formula, although you may end up with refrigeration issues, depending on your bug out situation. Look for single servings. Beware of the powdered formula as you may run short on water.
Baby food- my take on baby food is it is a luxury to a point. If you bug out with only protein bars definitly take baby food. If you are going to a shelter, you may be able to mash up some of your own food to feed the baby. Definitely pack a box of their favorite cereal, it can be mixed with the formula and wouldn't need further water.
Clothes- several outfits, we all know babies are messy. Perhaps keep some of those handme downs you were given that were already stained up or are a wee bit too big in the BOB. And check on sizes seasons frequently and make sure they still fit
Couple of warm blankets and some lighter ones to use as changing pads.
A favorite toy or 2
Diapers- always have a case by the BOBs ready to go. Me personally, I would have a case of wipes ready to go also. They can be used for everyone to clean up, not just baby. My baby is almost 6 and I still keep wipes- we all use them and have a container in each vehicle.
As to cloth- if you are going on a permanent bug out to hide out until TSHTF situation is over I would have cloth diapers available. You will run out of disposables, and cloth can be used for the next one that comes along. If you are just looking to disaster evac d/t flood, fire, earthquake, disposable is probably better, as the water resources where you end up may be strained.
infant tylenol and ibuprofen
tummy medication for gas
ear ache medications
a month supply of any Rx meds your baby uses, just like you would for yourself. Very important if baby has any chronic health issues such as asthma or reflux. You can get a supply built up gradually by refilling the meds as soon as they will let you. According to my pharmacists, most insurance companies allow refills up to 10 days before they are due. Several months of this can get you a month's supply that you can put back. Mark the calendar if you have to to remind you.
And here is something I just thought of- be sure your pediatrician's phone number is on your emergency numbers list.
A box of cheap zip type baggies to contain smelly messy clothes and diapers until you can get them washed out or properly disposed of.
OK, someone else chime in with what I didn't think of--