Lots, and we will love you forever if you help out.
In addition to any backsprites for mons you don't see above, here's a list, pulled from
the wiki:
Shruman - A longer, thinner, more active shush. Based on towercap.
Shushtaki - (Slate Stone) A mushroom man wielding a wooden blade and wearing a headband.
Hoarfrost - Ice-based Hoary Marmot. Will sleep with anything.
Mr.Tusks - A dwarf elephant
Skelefaint - A tiny skeletal elephant
Skelk - Skeletal elk
Skarmint - Skeletal marmot
Roatid - The Rotten Meat Dwarfomon
Miasmata - The Bleeding Stench Dwarfomon
Seegle - Sea Bird
Reegle - Large Raptor (the predatory bird kind, not the dinosaur kind)
Skeegle - Skeleton Eagle
Dolbok - A lithe and clever creature that wields a primitive weapon.
Dolbetuk - Friendly and intelligent, Dolbetuk is known more for its expressiveness and agility than for its prowess in combat. They are popular among trainers who enjoy cute monsters, but are often abandoned when the trainer realizes
Cat-5 : A large group of cat cables, starting to get tangled.
Cat-Clowd : A veritable wall of tangled cabling pokemon. Gets the battle effect "lag"
Unicorpion : A... well... just look at this:
http://www.bay12forums.com/smf/index.php?topic=42059.msg2639900#msg2639900. It is said that simply seeing this beast can give the heartiest of dwarves a heart attack.
Uncarp : (Water/Dark) : (Zombie Fish) : It is known to come onto land at night to seek out unsuspecting dwarves, drag them to the water, and hold them down until they drown.
Skelfish : (Water/Dark) : (Skeletal Fish) : Looking in many ways like a large skeletal barracuda
Urwhal : (Water/Dark) : (Skeletal Whale) : An enormous skeletal fish with tusks and a large horn jutting from it's head.
Perlihorn Normal : An adorable unicorn pony, it's voice is said to sound as sweet as a bell.
Unicron Grass/Steel: An adult perlihorn, the unicron's horn and hooves are sharp as steel, and it has a special connection with the magics of nature.
Perlestia Grass/Psychic: This creature has tapped into the power of light and magic.
Lunicron Steel/Fighting: This creature has tapped into the power of muscle and steel.
Magamette : A small stone elephant-like creature with flaming eyes.
Magaphant : A good sized stone elephant with flaming eyes and tusks. It has the ability to shoot magma from its trunk.
Vulcaphant : An enormous stone elephant with numerous tusks and spikes, and four burning eyes.
And we need more mons as well, of course, so if you want to create your own sprite for something not in the list (maybe from the ideas section below it), feel free.