It may seem extremely  crappy but I put it in my Fire/Water deck of mine
for one reason......Big Eggsplosion. I know you're thinking "What is so
good about that if you're deck is Fire/Water a grass move is useless to
you." Ah but the beauty of this move is it does not require grass energy
IT'S COLORLESS!!! And for every bit of energy on t\it you get to flip a
coin. Every head is worth 20 ponts of damage!! I don't know about you
but that could be extremely useful even against a Fire pokemon. Have an
Exeggcute in your bench and build his energy to oblivion and evolve at
just the right time and you can take out Charizards and Blastoises and
other Pokemon with high HP without a problem. So there you have
it....Exeggutor the underground powerhouse!!!!