Wasp covered in slime

Wasp gets ingested accidentally by Thor during battle and ends up getting regurgitated from Marvel Comic's the Ultimates 2 #5 (2005)

White Rabbit (and Arcade) fall into mud pit

White Rabbit (and Arcade unfortunately) fall into a mud pit. To add insult to injury, White Rabbit also gets egg in her face, literally. From Marvel Comic's Wolverine & Black Cat - Claws II #3 (2011) 

Happy Holidays from Comic Book WAM

(See Emma get a snowball in the face at http://comic-book-wam.blogspot.co.uk/2011/12/blog-post_24.html)

Spider-Woman covered in gunk

Spider-Woman gets covered in pink gunk as the Waxman melts all over her body in Marvel Comic's Spider-Woman #18 (1979)

Wonder Woman face down in the mud

Wonder Woman gets beaten and left face down in the mud by the god Apollo. From DC Comic's Wonder Woman #11 (2012)

Credit also to UMD's Nation_of_isWAM for this spot

Ms. Marvel pied

Ms. Marvel is not best pleased at seeing a pop-up model of her being pied...

It doesn't get any better for her when she then finds herself on the receiving of the aforementioned pie...

"Mmmm, boysenberry. For once he hit me with a pie I like."

Ms. Marvel gets a pie in the face from season 2 episode 22 of the Super Hero Squad "Missing: Impossible!" (2011)

Titania gets covered in muck

Nemesis of She-Hulk and supervillainess Titania gets punched by her rival, and sent flying...

Later on we find out that, unluckily for Titania, she had landed straight into a pile of muck.

Taken from Marvel Comic's She-Hulk #09 and #10 (2005) 

Emma Frost gets dropped into sewer water

Emma Frost gets dropped by Spider-Man and falls into sewer water. From Marvel Comic's X-Men #10 (2011)

Mary Jane pranked

Mary Jane on the receiving end of a prank involving shaving cream from Marvel Comic's Mary Jane #3 (2004)

Durham Red falls into mud

Durham Red of the Strontium Dogs flees an ambush- right off the top of a ravine and into a mud flat. From 2000 AD Prog #1785 (2012)

Credit to MrZero for this find