There was a good one in Thailand... we'd all gone out on the p*ss... my Grandma stayed back at the hotel, a bloody massive spider wandered in under the gap between the door and frame followed by a lizard. She's terrified of spiders but managed to take a pic... the lizard proceeded to stalk the spider to the middle of the room and chomp it with audible crunching.
If you don't like spiders don't go to Thailand!
another lizard/Grandma related one... she gets serious reactions to mozzie bites, we used to go visit her as a kid when they had a pub in Gibraltar, they had a lizard move into the bedroom which helpfully chomped all the mozzies and she didn't get bitten for years then while the rest of us got eaten alive! It slowly turned from greeny/brown to almost transparent so it matched the white walls