The scene in question can be found here Transcript: Randall: 'Wazowski! Where is it you little one-eyed cretin?' Mike: 'Okay, first of all it's "Cretan", if you're going to threaten me, do it properly'

But cretin is the commonly used insult, and it's not mispronounced. Via Google:

Cretin
/ˈkrɛtɪn/
noun
1. INFORMAL•OFFENSIVE
a stupid person (used as a general term of abuse).
2. DATED•MEDICINE
a person who is physically deformed and has learning difficulties because of congenital thyroid deficiency.

Similar-sounding words
cretin is sometimes confused with cretan

Similarly, Cretan:

Cretan
/ˈkriːtn/
adjective: Cretan
relating to or characteristic of the Greek island of Crete or its inhabitants.
"ancient Cretan pottery"
noun: Cretan; plural noun: Cretans
a native or inhabitant of the Greek island of Crete.
"on the road he meets a Cretan"

I was surprised to find zero commentary on this online given it's a 19 year old film, albeit a rather minor part of one. Google notes that the two words are commonly confused for one another given their relatively similar pronunciation, but considering that Mike corrects him I assume there's some intentional joke here - but I can't figure out for the life of me what it is. Given Crete is a Greek Island I assumed it might have something to do with Greek mythology but I can see nothing else that might back this up, Crete, unfortunately, has nothing to with Cyclopses, though I almost want to pretend it does and that this is a great, obscure joke.

I only actually came to rewatch this scene after a friend, who defended the use of cretin in a discussion of whether it should be censored from a video we were making on the basis, mentioned that it was used in the film Monsters Inc, but after a while, I noticed her pronunciation of the word was odd. It would be interesting to see whether this scene actually influenced people's pronunciation of the word, but that's a separate matter.

The scene in question can be found here. Transcript:

Randall: 'Wazowski! Where is it you little one-eyed cretin?'
Mike: 'Okay, first of all it's "Cretan", if you're going to threaten me, do it properly.'

But cretin is the commonly used insult, and it's not mispronounced. Via Google:

Cretin
/ˈkrɛtɪn/
noun
1. INFORMAL•OFFENSIVE
a stupid person (used as a general term of abuse).
2. DATED•MEDICINE
a person who is physically deformed and has learning difficulties because of congenital thyroid deficiency.

Similar-sounding words
cretin is sometimes confused with cretan

Similarly, Cretan:

Cretan
/ˈkriːtn/
adjective: Cretan
relating to or characteristic of the Greek island of Crete or its inhabitants.
"ancient Cretan pottery"
noun: Cretan; plural noun: Cretans
a native or inhabitant of the Greek island of Crete.
"on the road he meets a Cretan"

I was surprised to find zero commentary on this online given it's a 19 year old film, albeit a rather minor part of one. Google notes that the two words are commonly confused for one another given their relatively similar pronunciation, but considering that Mike corrects him I assume there's some intentional joke here - but I can't figure out for the life of me what it is. Given Crete is a Greek Island I assumed it might have something to do with Greek mythology but I can see nothing else that might back this up, Crete, unfortunately, has nothing to with Cyclopses, though I almost want to pretend it does and that this is a great, obscure joke.

I only actually came to rewatch this scene after a friend, who defended the use of cretin in a discussion of whether it should be censored from a video we were making on the basis, mentioned that it was used in the film Monsters Inc, but after a while, I noticed her pronunciation of the word was odd. It would be interesting to see whether this scene actually influenced people's pronunciation of the word, but that's a separate matter.