Image imported from derpibooru 
Original Description:
 
From the chapter Unsolved Selfie Mysteries
 
After Raph laughs at Timber for being afraid of Pinkie’s floatie, Mikey scares him with a cockroach. He and Timber then laugh at him for being afraid of bugs, with Mikey even telling Timber that Raph ran screaming like a little girl when he first faced Spy Roach and Scumbug and Antrax. But this prompts an angered Raph to hurl them both into the ocean. Rarity floats by and says she understands, having been dunked before.
 
 
Timber and Mikey getting dunked idea by me.
 
Mikey’s beach wear by TMNTony
 
Equestria Ninja Girls: Forgotten Friendship by DarkMagicianmon a.k.a Wildcard25.