This is the second of Pika's two most frequently used throws. Dthrow can start combos at low percentages, sending the opponent more or less directly above you (and slightly to the side depending on their DI), which allows you to utilt or uair them.
Dthrow is also imperative to Pika's grab game because it can chaingrab a large number of the cast. There are two types of CGs you can do with dthrow: buffered and unbuffered. For more information on buffering and the difference between these two types of CGing, see GRBG.
Buffered Dthrow CG Combos (Original Testing by Michael Hey, K Prime, The Truth!, RPK, & ESAM)
Diddy Kong: 0%-21% + regrab (fthrow > dthrow > grab)
Donkey Kong: 7%-26% + regrab (dthrow x2 > grab)
Falco: 0%-100% + regrab (fthrow x2 > dthrow x13 > grab)
Fox: 0%~100% + regrab (dthrow x14+ > grab)
Ike: 0%-62% + regrab (dthrow x9 > grab)
King Dedede: 0%-77% + regrab (fthrow x2 > pummel > dthrow x3 > pummel > dthrow x4 > grab)
Link: 0%-41% + regrab (dthrow x5 > grab)
Lucas: 5%-33% + regrab (dthrow x3 > grab)
Meta Knight: 0%-52% + regrab (dthrow x7 > grab)
Sheik: 0%-105% + regrab (fthrow x2 > dthrow x14 > grab)
Snake (ver. 1): 0%-83% + regrab (fthrow x2 > pummel > dthrow x3 > pummel > dthrow x5 > grab)
Snake (ver. 2): 10%-90% + regrab (fthrow > pummel > dthrow x10 > grab)
Snake (ver. 3): 0%-90% + regrab (fthrow to ledge > dthrow to 90% or below (must begin dthrow by 30%))
Squirtle: 3%-22% + regrab (dthrow x2 > grab)
Wolf (ver. 1): 0%-115% + regrab (dthrow x3 > pummel > dthrow x14 > grab)
Wolf (ver. 2): 0%-115% + regrab (dthrow x3 > fthrow > dthrowx13 > grab)
*Note: Not all of these CGs start with dthrow; however, they all center around buffering dthrow at some point.
Unbuffered Dthrow CG (Original Testing by Ruuku)
Captain Falcon: 0%-80%
Fox: 0%-70%
Sheik: 0%-60%
Wolf: 0%-30%
*Note: Sheik and Captain Falcon can DI towards you and footstool out of the unbuffered CG on the first throw, so this is not a true chaingrab on them. However, many opponents don't know this, so it's worth trying if you can get the grab. Otherwise, use the fthrow or buffered dthrow CG.