Bestia mecánica

Can attack or block even if it has no counters.

Loses a counter even if it is affected by a Fog-like effect which prevents it from dealing damage.

Clockwork Beast’s last ability resolves, you can choose to put fewer than X +1/+0 counters on it.

If Clockwork Beast has seven or fewer +1/+0 counters on it when its last ability resolves, it can wind up a maximum of seven such counters on it. If it has seven or more +1/+0 counters on it, the ability will have no effect.

This is a change from the most recent wording. Now, if some other spell or ability causes +1/+0 counters to be put on Clockwork Beast, it can wind up with more than seven such counters on it.