i’m gonna just do the main babes b/c i’m still not done w/ the show and i feel like i don’t have a good grip on everyone’s character!! so this is just the gaang + zuko
aang is probably really ticklish and i think you could argue that being canon b/c of how giggly he gets whenever appa or momo lick/nuzzle him. he’s just so bubbly and smiley and you know he thinks tickle fights are super fun, and he absolutely starts them (even if he knows he can’t finish them, specifically with sokka i think). he’s really ticklish on his neck and stomach, his laugh is so loud and boisterous and sweet. as a ler, he’s really ruthless and loves to strike with surprise and tickle til they tap out, because the avatar doesn’t do anything half-assed.
katara is ticklish too, but surprisingly not as much as you’d think. she’s sokka’s little sister, she’s used to getting tickled and has found her fun ways to escape or hide ticklish spots. she’s ticklish on her sides, thighs, and feet, and doesn’t like being tickled quite as much as she likes dishing it out. i feel like with katara, being tickled is something that really depends on who it is. with sokka, it’s something she’ll groan about and kick him off and get revenge, but it’s still playful. with aang, she lets him do it because he has so much fun, but he knows she’ll get him back. she has to trust someone, so it takes a while before toph and her exchange any tickly touches. as a ler, she’s teasy and ruthless.
sokka is actually probably the more ticklish sibling, but only because he’s worse at hiding his ticklishness. he’s ticklish under his arms and all over his legs, especially his knees. his laugh is super loud, uncontrollable, and high-pitched. i just know that suki would tease him about having a “girly” laugh. sokka is also probably the most skilled ler of the gaang simply because he’s the oldest and has a little sister who he used to tickle a lot, so he’s good at pinning his target down and finding their ticklish spots with ease. he’s very much a tease in the “don’t stop? sure, i won’t stop!” or the “don’t what? tickle you? okay!” kind of mind games.
toph is actually very ticklish and finds this fact super annoying. she’s usually really good at catching onto to when someone’s going to tickle her and striking first, with heartbeats and footsteps and all that. if someone can sneak up on her, though, her laugh is actually really sweet and childish and giggly, and she always tries to muffle it. her feet shouldn’t be sensitive since she’s always barefoot, but since she uses them to sense so much, they’re sensitive to any sensation, but she hates having her feet tickled and will absolutely kick you in the face and/or earthbend. her stomach and sides are fair game though!!
zuko is probably the most ticklish of the group, maybe second to toph, and no one expected him to be so sensitive but he literally crumples at a poke. his worst spots are his ribs and underarms, and his laugh starts off soft and giggly and slowly turns into this uncontrollable, sort of raspy laugh that is so contagious and cute. zuko secretly kinda likes being tickled, even though he thinks it’s really embarrassing, because it makes him feel like part of the group, and also reminds him of childhood and his mom. he’s not a very good tickler because he’s literally not tickled anyone maybe ever, except like maybe azula when they were super super little, like 5 and 3 type age, maybe given mai a little tweak to the side, but really, he is not good at it, he needs a tickle tutor, he just kinda pokes and hopes for a laugh?? he would pick up on it quickly if someone helped him figure it out, though. he’s not teasy but he probably giggles along with the lee!!!!!!