The Gate Guardian

Indestructible, Reach
If The Gate Guardian were to be the target of
a spell or ability, remove all counters on this creature and destroy that card.
Every time The Gate Guardian destroys a creature, add a +2/+2 counter onto it.

It is the avowed belief of the Founder that the gate which SCP-001 guards may be the gate to [REDACTED] based
on correlations with ancient Babylonian texts. In which case, one can deduce that the entity known as SCP-001 may be [REDACTED]. —Dr. Clef's Proposal