Fruit Plum
It inflates to a certain point, then shoots thousands of bubbles at medium range until it returns to its normal form.
Cost: 125❤Unlock: defeat Mega Plum 10 times.

The Binding of Isaac fangame, heavily inspired by Plants vs. Zombies · By
Seraphim: 200 ♥, Shoots high damage homing tears at a slow pace, Seraphim tears are slower than other tears.
Strawman: 225 ♥. Shoots in 3 directions, NOT LANES.
Rotten Baby: 150 ♥. Shoots a friendly fly. Unlock: Let a friendly fly kill an enemy,
Water Baby: 125 ♥. Shoots slightly faster than Brother Bobby, explodes in a tear ring when killed.
-0- baby: 350 ♥. Immune to any type of damage, immobile by Hardy, Unfreezable, dies after10 seconds. Unlock: Loop 4 times.
Butthole Baby: 150 ♥. Shoots poop tears that have a chance to poison enemies.
Bloodsucker Baby: 200 ♥. Shoots red tears, when it kills an enemy it makes it drop a small heart. Unlock: Beat a level using only Fork + Spike Baby as a heart producing method.
Boss Baby: 150 ♥. Does extra damage the more health an enemy has. Unlock: Beat all bosses at least 3 times.
Pubic Baby: 100 ♥. Same as Brother Bobby but has extra hp
Freaky Baby: 175 ♥. A Chomper like baby, instead of insta killing an enemy, it does high dps in short range.
Eyeless Baby: 150 ♥. Shoots a short range creep trail at enemies.
Cracked Infamy Baby: 150 ♥. Resists a fatal attack, removing it's mask permanently unless Full Healed or Power Pilled, Alternates between a normal tear and a blood tear with extra damage. Unlock: Kill a masked mulligan without removing its mask.
I won't add damage values, health, cooldowns, or costs, because I'm kinda terrible at balance, but here's some ideas:
Lil' Abaddon: Charges up, click on it when fully charged (like Coconut Cannon or similar) to deal high damage to everything in a 3x3 radius. Ignites Paschal candles in dark-red flame, making them fire tears slowly.
Reaper Baby: Somewhat defensive, deals damage to all creatures in up to two tiles in front (similar to Bonk Choy, referencing Samael).
Infestation: When killed, the monster that killed it is infested with flies. When that monster dies, many flies similar to that of Parasitoid's fly out of it.
Halo of Flies: Placed on top of an existing baby, somewhat defensive (Pumpkin is underrated)
Lil' Spewer: Slow firing, damages all grounded enemies in front of it. Can be given pills to have different firing patterns. Fires faster when placed next to Acid Baby.
Troll Baby: Instantly explodes, dealing massive damage in a 5x5 area. Makes a crater below where it was placed, making it impossible to place anything in that space for the rest of the stage (Doom Shroom).
Ball of Bandages: Similar to Cube of Meat, but with less health. Reflects projectiles that would damage it.
Worm Friend: Instantly kills the first enemy to touch it, disappearing in the process (Tangle Kelp).
Horn Baby: Initially fires quickly, but slows down over time. Dies after a certain amount of time. (referencing Chronos)
Salt Baby: Charges over time. When at full charge, click it and then click an unoccupied square. Salt Baby will jump to the square, dealing large damage to all monsters in the square, then jump back. (Edith)
Dr. Fetus Baby
Behavior: He Shoots Little Bombs 3 Tiles In Front Of Him (not killing any babies) That Attacks Multiple Enemies In a 3x3 area around the bomb Dealing A lot Of Damage (but not one shoting anything) For Example. 3 Explosions To kill a Gaper. (Also after a Enemy is 2 tiles away from him, it stops in front of him) He sees Enemies 5 tiles away from him.
Cost: 250❤
Unlock: No Unlock