Royal Amalgam

Shifting Form — Whenever you tap an untapped Slime you control, choose one:

Royal Amalgam gains flying until end of turn.

Royal Amalgam gains first strike until end of turn.

Ooze Rebirth — If Royal Amalgam would die, exile it instead. At the beginning of your next upkeep, return it to the battlefield as a 1/1 Purple Slime creature with all of its abilities.
"Even when cut down, the knight reforms—
smaller, but never weaker."