Munchkin zombies. Mojo card: Plague zombie question

[nilesface]

I tried VERY hard but could not find any relevant info to my question.

Plague zombie: "death breath: against monsters of level 11 or higher, you can discard up to 3 cards from your hand for +2 each to your side"

This is a mojo card, the zombies equivalent to a "race" card.

My question is, what exactly does the "level 11" mean? Is that combat level, or the level listed on the monster card?

Example: Player using the plague zombie, kicks down door, the card is a level 6 monster. The level 6 monster says "+5 if today is saturday" it is saturday.
Monster's combat level is 11.
Can the player using plague zombie discard cards for +2 to his side?

Is the situation the same if the monster exceeds level 11 combat by a monster enhancer or one-shot item?