Oops vacation may have sidetracked me a tad
120 HP
120 Attack
60 Defense
60 Special
65 Speed
BST: 425
High HP + lower defenses look nice to discourage use of Special moves since we want to use Haze to bypass reflect, but I do not envision Water STAB being too overbearing considering the many Water resists in the metagame + Chansey, so it's not a major concern. Haze should still provide some cool value given the wide array of things it can do and the very obvious matchups it helps with.
120 HP puts us outside of the 4HKO range on Seismic Toss, which is valuable given we want to be good into Chansey. 120 for Attack as well is capable of 3HKOing Snorlax, [159-187 (30.4 - 35.7%) -- 37.9% chance to 3HKO], while having good odds to 2HKO Chansey [335-394 (47.6 - 56%) -- 83.5% chance to 2HKO].
Our defense is good enough to live two hits from Lax comfortably, so with smart play we can come in on it and threaten haze + sleep. Tauros meanwhile is sketchier, 2 Slams into Hyper Beam always KOs, and if Slam crits it can just Beam us next turn. We do not threaten a 2HKO back, so we aren't winning this exchange assuming Sleep Clause is in effect (I don't see why you'd risk getting your Taurus slept in the first place anyhow). Chansey isn't too bad barring Freeze or Sing, so this +Chansey, =Lax, and -Tauros MU chart seems quite nice.
Starmie is incapable of OHKOing us and cannot 2HKO with Psychic into -SpDef Psychic, and Crit Psychic + Psychic isn't a guaranteed KO either, letting us check it decently and threaten Sleep. Alakazam meanwhile is a much more difficult situation, as it can manage to score 2HKOs on in the same hax scenarios Starmie struggles with.
The weakest Razor Leaf in OU is Dracolilla which has a 76.9% chance to OHKO on the crit. We always die to any other users of the move, and they are all capable of outspeeding us when healthy.
Exeggutor is weird because we don't threaten it outside of Sleep, outside of potential coverage, but there's a good chance it wants to avoid being put to Sleep in the first place. Lagosnow and Cloyster can be similarly frustrating given their good typing into us, and both outspeed.
To cap it all off here's a very simplified idea of what we MU against so far:
Strong (can come in on easily or threaten with damage and/or sleep)
:
Neutral (able to check or frustrate but can still pressure us situationally)
:
Weak (if these decide to come in on us we're probably in a bad spot)
: + prior CAPs