captioning shows the first time he does that "SSFUP AOCOC ROF OOKCUC  MI" (which is IM CUCKOO FOR COCOA PUFFS spelled backguards); and "TTIBBAR  YLLIS. YLNO SDIK ROFERA XIRT" (that stands for TRIX ARE FOR KIDS ONLY.  SILLY  RABBIT also spelled backguards).