Zootopia: "I just wanna say you're a great dad and just a real articulate fella."
Register: Informal speech
Evidence of informal speech: 1) the use of wanna instead of want to, 2) the use of real as an adverb (instead of really) 3) fella as opposed to fellow. Fella is marked in American English as southern, western or mid-western
Juxtaposition: Informal register speech with a rather formal word: articulate, which means well spoken and/or who expresses himself well.
Conclusion: using the word articulate in the context of what is, overall, informal speech produces a comic effect.