I'm not sure how exactly it's triggered , but there's something about summoning Tibbers that brings out this really enthusiastic laugh out of her, and for some reason, this specific laugh isn't really listed in the wiki or anything. Has any 
player out there experienced this before?
RiotRiot Whist7 votesShe has at least 2 laughs she can play upon casting tibbers which are part of a list of audio clips she'll play that are chosen randomly.
Not sure why the wiki doesn't have them.
DocRedgrave2 votesPeople probably weren't paying too much attention to it. This seems like too much of a minor detail for people to care about.
Nexiel1 votesIt was just one of those thing that irked me for so long. I'm glad Whist shined light down upon this mystery.
PowerBurger2 votesI've definitely heard it before, it sounds like a sadistic taunt of a laugh.
Final GirI2 votesI have somewhere around 40+ games with Annie in ranked and I always hear it and it's honestly kind of creepy.
TDeadFather1 votesVideos or didn't happen
Final GirI1 votesVideos or didn't happen
Just go play a match or two as Annie o.o
TenSlashTen1 votesaudio clip. youtube. no idea what you mean.
Jubbinaut1 votesThe only special laugh I know of from her occurs when she casts the last spell to prep her stun.
Never heard one for summoning Tibbers.
TIBBERS R US1 votesYour computer is haunted I've play 1000 game with Annie never heard it.
Nexiel1 votesI may have figured it out. After experimenting in custom bots, it seems like this unique laugh is nothing but another "quote" she says upon summoning Tibbers. I could still very well be wrong, but considering how random it is, I think it's the system cycling through that laugh instead of the usual "TIBBERS!"