sorry this is a big one
a few baby ideas as well:
ball of bandages - about 50% the health of a cube of meat, but each enemies have a chance to become charged when attacking it. the chance increases for on enemy for every attack it does.
lil' brim - costly, requires to charge. when charged, can be clicked to release the brimstone beam, dealing 5 ticks of damage to every enemy in row. when powered up, deals 7 tick of damage
robo-baby - fires weak but piercing lasers, has a slow fire rate. when powered up, deals more damage per laser
succubus - has a 5x5 damaging aura around itself. the damage is much less than spike baby's. more damage when powered up
incubus - locked behind unlock, attacks and abilities are dependent on your passive items(some items grant the same effect, some don't grant any). fire rate increases based when powered up.
boiled baby - costly. randomly spews(lobs) many projectiles at enemies in its lane, with low accuracy. low fire rate, increases the amount of projectiles when powered up.
seraphim - costly. has homing, a slow fire rate and a lot of damage. increases fire rate when powered up.