It's the Easter Beagle, Charlie Brown (1974)

Plot

Charlie Brown, Linus, and their Peanuts friends embark on a spirited egg hunt as Easter approaches. As they search, they think they've caught a glimpse of the Easter Bunny. However, the creature in question resembles their beloved beagle, Snoopy. The gang is left wondering whether they’re witnessing a magical moment or if Snoopy is simply up to his usual playful antics. The quest for Easter joy becomes a delightful mix of excitement and confusion, highlighting the charm of childhood imagination.