Type: Normal
Base Stats 160 HP/110 Atk/65 Def / 65 SpA / 110 SpDef
Immunity / Thick Fat / Gluttony HA
Pros:
-Absolutely massive HP stat and great Sp. Def makes it hard to take out with a special attacker.
-Thick fat reduces potential damage from Chien Pao and Chi-Yu, making it a good switch in to them.
- Solid movepool befitting that of a normal type, with a ton of options for coverage moves, elemental punches, zen headbutt and high horsepower are a few notable examples
-Immunity removes the chance of toxic putting this bear in hibernation, and
Cons:
-65 Defense isn't great, especially with the amount of physical attackers and fighting types like Great Tusk running around.
-VERY slow, meaning you'll want to use this on a trick room team if you want it to pull it's weight.
-At over 1000 lbs, Snorlax takes a lot of damage from grass knot and low kick, the latter of which posing a significant threat when combined with the aforementioned mediocre defense stat.
Terastylization:
Honestly, I'm having a hard time coming up with ideas for good tera types for this one, you could go with Tera-Grass and utilize thick fat nullifying 2 of the four things grass is weak to and use seed bomb as reliable STAB, or stick with Normal Tera to make double edge/body slam hit even harder.
Potential set:
1 ton tank:
Snorlax @ Leftovers
Ability: Thick Fat
Tera Type: Normal/Grass
EVS 252 HP /126 Atk / 126 Def / 4 SpDef
Moveset
Seed Bomb
Body Slam
High Horsepower
Ice Punch
This set capitalizes on Snorlax's stellar attack and shores up it's not so great defense stat while giving it some attack to keep it from being passive. Tera Grass turns the tables on attempts for the opponent to use a fighting move on it and Seed Bomb becomes STAB under its effects. High horsepower and ice punch are there to threaten any poison or flying types that might try to rain on Snorlax's parade. It isn't foolproof though, as a weezing with levitatecan ignore the high horsepower.