Niiden (Ne) - They (24)

"Niiden" (theirs) is the form of "ne" (they). The translation is something like "They shouldn't make this sound". "Niiden" is genitive and I'm not sure why this form is used here.
On this picture Viivi asks Wagner about strange sound his knees are making.
The original comics may be found here.

Sano - Say (25)

"Sano" means "say", it's number 25 on the most frequent Finnish words list.
Here Wagner (the pig) tries to persuade chicken to say different Finnish words.
Original comics may be found here.

Kaikki - All (26)

"Kaikki" means "all", it's number 26 on the most frequent Finnish words list.
The whole phrase translates as "All my bones are smashed in pieces".
Original comics may be found here.