There is the beastmaster ranger but sadly that only allows CR 1/4 and medium, Crocodiles are CR 1/2 and large, I too wish my beastmaster ranger could have a croccy boi

Quote from Shrapucino >>

There is the beastmaster ranger but sadly that only allows CR 1/4 and medium, Crocodiles are CR 1/2 and large, I too wish my beastmaster ranger could have a croccy boi

Crocodiles are fairly slow-growing, so you could probably discuss with your DM the possibility of using a "juvenile crocodile", which could be a re-skinned Dimetrodon with minor stat modifications, as they are medium-sized aquatic biting "reptilians". See https://www.dndbeyond.com/monsters/17238-dimetrodon. The description even says "It hunts on shores and in shallow water, filling a similar role as a crocodile."

To make it more croc-like, I'd change the proficiency in perception over to stealth, make the speeds equal to the croc (20 30 rather than 30 20), give it Hold Breath and maybe reduce the time to 10 minutes, and keep the dimetrodon bite. This bite actually does more damage than the crocs (9 on average vs 7) but has a lower chance to hit by 1, and also lacks the grapple. The HP and AC are identical for both.

I recently saw a post about Nile crocodile attack fatality rates, and it inspired me to do math.

If a crocodile attacks a commoner (AC 10) it will hit 75% of the time (+4 to hit, 5 or lower needed to miss). Given that the attack hits, there is a 90% that the commoner (4 hp) is toast (1d10+2, commoner only survives if the d10 is a 1). This means that the overall fatality rate for a croc attacking a commoner is 67.5%.

The IRL fatality rate is 63%. This stat block is startlingly accurate.

Ranger allows you to have a beast companion of CR: 1/4 and it can be no bigger than medium, but you probably could get your DM to allow the small upgrade. I bet you could ride it too. That’s what I’m planning to do with my next character.

Quote from BerkayKarsli >>

If you tell this to your DM at the beginning, S/he can put a crocodile as your companion like an ordinary PC and change the CR of the game for this.

Quote from GenericRpgNPC01 >>

Berkaykarsli
You are making a lot of assumptions
Like that just because you ask for a crocodile that means that you, regardless of class/subclass will get one
Also the wording suggests you think they HAVE to.
You are incorrect.
You can ASK (not TELL) you DM if they might consider it. But they are fully within their rights to say no, In fact they would be showing favouritism if they let you have one

 Like Generic RPGNPC01 said, you would need to roll a very high persuasion check on the dm.  A crocodile is no small thing, also again like GenericRPGNPC said you're wording it like you're almost forcing them to and you want to keep good relations with the DM in a game, after all they can drop 17 meteors on you if they please

Let's remember commoners are AC10 HP4. Crocs have a 75% chance to hit them and 90% chance of dealing enough damage to kill them instantly.

You can summon 4 crocodile's with Conjure Animals.  Welcome to the water fight! 

I want a talking croc as a pet like the talking meowth from pokemon

Quote from Shrapucino >>

Quote from BerkayKarsli >>

If you tell this to your DM at the beginning, S/he can put a crocodile as your companion like an ordinary PC and change the CR of the game for this.

 

Quote from GenericRpgNPC01 >>

Berkaykarsli
You are making a lot of assumptions
Like that just because you ask for a crocodile that means that you, regardless of class/subclass will get one
Also the wording suggests you think they HAVE to.
You are incorrect.
You can ASK (not TELL) you DM if they might consider it. But they are fully within their rights to say no, In fact they would be showing favouritism if they let you have one

 Like Generic RPGNPC01 said, you would need to roll a very high persuasion check on the dm.  A crocodile is no small thing, also again like GenericRPGNPC said you're wording it like you're almost forcing them to and you want to keep good relations with the DM in a game, after all they can drop 17 meteors on you if they please

 or summon tiamat

Tasha's cauldron of everything. any creature with a CR of 1/2 or lower can become a sidekick.

i love this thing as a druid. my party gets so much stronger due to the grapple and it does decent damage. wish it could death roll and/or disarm the enemy. also swallow small or tiny creatures would be cool but unnecessarily strong as there are better creatures for that like the giant toad. but better AC and a death roll attack on restrained creatures and being able to clamp down on the enemy as a bonus action. someone make this.

many men, men many many many men, fish death on me 

They should 100% have a tail attack

They are.

There should also be a grapple/death roll attack, something like the giant frog's bite/swallow.

special sights camn see nything anywhere in the water