Shark
Shack.
Hacks
(Illegal move!)
Hack
Lack
Black
Slack.
Stack
Tack
Also, I wouldn’t really call it an illegal move. He moved a letter…
Tick
(I think he meant it as a pun.)
But moving a letter isn’t in the rules!
Stick
Strict, much?
Stuck
Struck
Truck
Tuck
Buck
Luck.
Lick.
Flick
Fluck