I read this and accidentally some dice. I am not certain that I want to join... Also i have no idea what costs should be, or if abilities would be terrible.
Monster: HP/AP/MP/die/ability: ability description; Other ability: other ability's description.
Blue Jelly: 10/10/1/1 Too weak, nobody takes this.
Flame Jelly: 10/10/1/2/Flame Burst: respond to destruction by reducing adjacent enemy HP by 3.
Acid Jelly: 10/10/1/11/Acid Burst: Respond to destruction by reducing adjacent enemy AP by 3.
Glue Jelly: 10/10/1/10/Glue Burst: Respond to... MP by 3.
Grease Jelly: 10/10/2/9/Grease Burst: Respond to destruction by increase adjacent enemy ability cost by 3.
Poison Jelly: 10/10/1/3/Poison Cloud: Normally deal 10 damage to all enemies within 3 tiles.
Corridor Jelly: 30/30/1/7/Transparent Deception: Respond to enemy movement by immediately moving adjacent to them and attacking. Cost increases based upon the distance Corridor Jelly travels with this action and decreases based upon the distance that the target has travelled in its current movement.
Slime Jelly: 24/20/2/4/Split: Respond to being attacked by nullifying that attack, halving its HP, then adding a duplicate of itself to an available adjacent space.
Queen Jelly: 20/20/3/8/Spawn: Normally create a duplicate of a 10-AP ally on the field and place it in an available adjacent space.
Knight Jelly: 40/40/3/1/Mimic: Respond to an attack upon a Queen jelly by exchanging position with that queen jelly and receiving the attack in its place.
Jelly Pit: 50/50/0/11/Slime Filled: Normally destroy an ally to change HP to 50; Slimy Depths: Respond to a monster being moved by an ability by immediately attacking that monster.