I r fabulous!
(Oh god, I shall never say that again, EVER.)
Okay Chocofresh, since we didn't even attack once last turn, let's get to it!
First, duplicate yourself to irritate the lil' turtle! Then block his movement with Sand Tomb, so the following earth quake is unavoidable by squirtle shenanigans!
In case he tries some nasty status infliction on the first turn, use dig instead, prepare a substitute underground and dig back up afterwards with mighty power!
[Double Team ~ Sand Tomb ~ Earth Quake]
Sub: [Dig Down ~ Substitute (Medium) ~ Dig up]