Keyleth, Voice of the Tempest

At the beginning of combat on your turn, up to
one target land you control becomes an X/X Elemental creature with trample and haste until
end of turn, where X is Keyleth's power. It's still
a land.
Landfall — Whenever a land enters the battlefield
under your control, put a +1/+1 counter on target creature.
"Hey, guys... We're friends, right?"
"Worse. We're family." -Keyleth and Percy