A fair while ago someone said something like 嘘だぴょーん！ in a comment.
But what kind of a connotation and usage does ～だぴょん have? Can it be used in a kind of humorous sort of way?
Edit: Realized it was actually 嘘だぴょーん！.
The question was revised since my initial comment, which I will add as an answer.
だぴょん (or だぴょーん) is a final suffix equivalent to だよん or だよ. It adds a sense of cuteness owning to the fact that ぴょん (or ぴょんぴょん) is the way in which something (such as a bunny) hops or bounces.
(@Dono's correction/answer allowed me to find out a lot more, so I thought I might try to add a bit about the expression 嘘ぴょん.)
According to Zokugo-dict, 嘘ぴょん is an expression which first appeared around 1986, and it's used when speaking one's mind after someone tells a fib. It apparently isn't used for really serious lies, only for exaggerations/dramatizations etc which could end up as jokes.
Apparently 嘘ピョーン was at number 1 at Goo's 2009 今でもつい使ってしまう死語ランキング "ranking of dead language which is unintentionally used even now."
だぴょーん！rather thanだびょーん！– cypher Apr 21 '12 at 2:42