Teenage Mutant Ninja Turtles (2003) (2003)

S04E22 Adventures In Turtlesitting

As the mutant outbreak looms, the Turtles decide it's best to leave Donatello under the watchful eyes of Casey and April while they tackle the crisis. However, Donatello isn't merely unwell; he is actually experiencing the final phases of a secondary mutation. His brothers remain unaware of his true condition, leading to unexpected challenges for Casey and April as they care for him during this perilous time.