Outside of Raid Boss tyranitar and a few others, there is little doubt that snorlax is definitely one of the tougher Raid Bosses in all of Pokemon GO. On top of being a Level 4 Tier Raid Boss with a staggering combat power Level that eclipses the mark of 25,000, Snorlax has one of the highest Stamina Stats among all Raid Bosses. A Regular Snorlax alone is so very difficult to defeat because of this stellar statistic, and it makes Raid Boss Snorlax all the challenging when trying to bring it down.
Because Raid Boss snorlax has such an incredible combination of combat power and Stamina, it will take a group of many trainers in order to overcome this power, preferably 6-10 people participating in the Raid. This amount of participants is very similar to that of Raid Boss Tyranitar, who actually has roughly 10,000 more Combat Power. But since Snorlax has the ever-impressive Stamina that it does, it usually takes this same amount of people in order to win in its Raid.
After having enough players to defeat Raid Boss snorlax, it is recommend to have plenty of machamp, heracross, dragonite, rhydon and even donphan ready for the battle,. Machamp & Heracross are always your best option when it comes to battling Raid Boss Snorlax - much like tyranitar - as these two are the strongest Fighting Type Pokemon currently in Pokemon GO. Both have plenty of Fighting Moves it takes to defeat Snorlax, but since Machamp isn't Region-Locked like Heracross, it usually is the most used Pokemon again Raid Boss Snorlax.
From there, many players tend to use a combination of dragonite, rhydon and donphan. Dragonite continues to be one of the best Attackers in all of Pokemon GO, making it one of the best options for players no matter who the Raid Boss is (outside of Lapras). Both Rhydon & Donphan are stronger, defensive Ground Types that brush off Snorlax's hits as if they are nothing at all, but both also are given a number of Fighting Type Attacks to do further damage to this behemoth of a Raid Boss.
Much like tyranitar, snorlax will be one of the more difficult Raid Bosses to defeat, no matter how many players you are raiding with and no matter what Pokemon all of you choose in the Raid. Snorlax will always be a challenge for any player and group alike, but like all Raid Bosses, it can certainly be defeated if you have enough teammates aiding the cause.