This is a great shapeshifting option when you find yourself facing an ooze.

the only way for someone to become one is to be a level 21 druid.  Which isn't possible on this site.  Or use one of two spells Polymorph (debatable) Shapeshift or Shapechange can't remember which is correct.

What's stopping someone from using polymorph to become one?

Didn't know about that spell, looked it up and correct the previous comment.

actually with polymorph you can turn any PC into it starting at 7th level

KING KONG

me like big ape

This form is the best Polymorph form, available right when you get the spell.  +9 to hit is better than most L7 PCs +7 to hit, and 22*2 = 44 damage is better than any class'.

This is best used on a Lvl 7+ PC who has exhausted their resources (a monk out of Ki or a spellcaster out of slots). It can also serve as a sudden infusion of HP if they are near death.

As a Huge creature it can shove and grapple other Huge and even Gargantuan ones.

For a truly ridiculous situation, cast it on a Raging Barbarian. They have advantage to grapple or shove that Ancient Dragon (+9 Athletics!), they take half damage from physical attacks, and so on.

And since when has going King Kong on stuff not been awesome?

31 feet high jump including reach, (3 + 6 (strength mod), plus 15 feet height times 1.5 = 22)

Why?

Quote from Myaric >>

This is a great shapeshifting option when you find yourself facing an ooze.

 Why?

the ooze can't swallow you, or if you are swallowed you're too big to be contained by it.

Quote from Pomodoro >>

Quote from Myaric >>

This is a great shapeshifting option when you find yourself facing an ooze.

 Why?

The size and reach keeps you safe from (most) ooze’s engulf features.

This is my go-to "combat spell" for my Abjurer.  Mage armor, then big monkey time!  What's better than a giant ape?  A giant ape with mage armor and an arcane ward.

They can use  shields. Two more AC

Look at Gargantuan ape in home brew if you like this one

According to the wording of the multi attack you only get one Rock attack. The button to send to roll 20 causes you to make 2 rock attacks.

Nothing.  My level 11 wizard used it to great effect this last week

I think that's up to the DM, I talked to my DM about poly-morphing myself, and he set the rule that it must be a creature must have an intelligence of 3 or higher. this seems fair as that creature must be capable of concentrating on the spell.

It works wonderfully against a Balhannoth