Something allegedly fantastic or good that you know to actually be unbelievably shitty.
Person A: Everyone likes dogs because they're so great. You like dogs, right?
Person B: Yeah, dogs are shitastic.
The felling that over comes a person after taking a shit that makes you feel good.
Tim was feeling like shit all day untill taking a massive shit now he feels shitastic.
i had the most shitastic day when everything was going wrong AND THEN it rained
Something or someone so amazing, horrifying, or fantasical that is makes one have the feeling of or actually shitting
Driving on the parkway today was shitastic!
Dude, that trick was shitastical!
A:Oh My God I think I shit my pants!
B:Why?
A:I met Robert Pattinson!
B:He's so shitastic!
something so fantastic that you want to add profanity to get your point across
We just won the game, that's shitastic!
something that sucks balls, but you want to give a positive spin on it.
-It's really boring, you watch a video then take a quiz on it.
-Shitastic.
Something so disturbing but, so amazing.
Person 1: That guy just shot a bottle rocket up his ass.
Person 2: Oh my God, that's shitastic