Matatoomba, Ethereal, Critical Damage

[sismis]

In Necromancer expansion, Matatoomba has attack modifiers
Ethereal
Critical Damage.
Its kinda awkwardly spelled - I presume those are two abilities since each is in its own line, and I know what Ethereal does. What is Critical damage? All damage this creature does is considered critical? I cannot find in Mage Wars nor Academy rules any explanation.

Thnx!

[Reddicediaries]

Your guess is correct.

[sismis]

Thank you!
I guess I'll need to make some Academy Codex since keywords are not explained in Expansions I have nor in Rulebook ("Will be explained in further Expansions").