In the very first episode. "The Pastmaster Always Rings Twice", he briefly rummages through Callie's purse while at the museum; he finds a tube of lipstick, then eats it. Plus Feral's comment- "Throw a net over that guy!"
And before that, the immortal line from the Enforcer pilots: "You have the right to remain buried!"
And the exchange with Mayor Manx's reaction to this latest crisis:
Manx: (on phone with Feral) You won't do anything to my city hall until I find out who this kat is and what he wants! (hangs up)
Callie: He's an 800-year old sorcerer with a mystical spellbook!
Razor: Piece of cake, just remember, "always cut the red wire." [opens the bomb, sees they're all red] Augh, Dark Kat, you miserable psycho!
From "The Metallikats", Chance is busy trying to watch a "Scaredy Kat" marathon while Jake is trying to tell him about the Metallikats going after Mayor Manx- when he mentions Callie might be danger, Chance continues laughing, then he stops- a Beat, then Toon Physics kicks in, he runs off screen and is instantly suited up in his flight suit.
The revelation about Morbulus in "The Giant Bacteria":
Razor: Whoa, he does have eyes in the back of his head!