Cow and Chicken (1997)

S2E1 Fluffy the Anaconda

When Mom and Dad give Cow the green light to adopt a pet, she opts for an anaconda. After the snake consumes Chicken, Cow is startled to hear what she believes is Chicken's voice coming from within the snake. Convinced that the anaconda can mimic Chicken, she names it Fluffy. As time goes on, Fluffy develops a fondness for Chicken, who becomes its regular meal.