Fighting the Common Cold - OSR Style

I'm currently fighting some version of "The Common Cold", otherwise know as the "Coughing, Sneezing, Stuffy Head Fever and I Can't Rest" Illness. So, I've decided I want to kick it's ass, and for that I'll need to make it an OSR Styled monster.

Common Cold
Hit Dice: 1 to 4
AC: 4 [15]
Attacks: 1 attack per round / damage as HD 1HD 1-3 dam, 2HD 1-4 dam,
3HD 1-6 dam, 4HD 1-8 damage
Saving Throw: As HD
Special: Heat does double damage, Cure Disease is Save or Die, Successful
hit causes disorientation for 2-12 days (-1 Hit, -1 / 5% skill checks) unless save
Move: 6 Fly 12
Alignment: Chaotic Annoying

There's the common cold, and then there is The Common Cold. No one remembers which long dead wizard created The Common Cold while trying to find a cure for the common cold, but it no longer matters. His creations have been unleashed upon the world, and as they need host to breed they will be found everywhere from dungeons to rooftops and in between.

Smaller Common Colds (1 and 2 HD) barely reach a foot in height and are fairly translucent. As such, they have a 50% chance to surprise unwary prey. Larger Common Colds stand 2'+ and lack that ability, but have been known to split themselves into smaller HD creatures to achieve such an effect. A 3 HD Common Cold can split into 3 1HD Common Colds or 1 1HD Common Cold and 1 2 HD Common Cold.

Common Colds reproduce by "infecting" a host. A character struck by a Common Cold in combat must make a save vs. disease at the end of the combat (one save no matter how many hits). Failure means he is now incubating 2d6 Common Cold "babies". Over the course of the next 2d6 days, these babies will leave his system as droplets sneezed or coughed out. They can't be seen or harvested.. In approximately 2 weeks, these babies will become 1 HD Common colds