COGGERS in a BTTV emote which is a variant of the POGGERS emote, that is a variant of Twitch’s PogChamp emote. The word COGGERS is a portmanteau between the words COG and POGGERS. It got the name because the mote depicts the POGGERS emote inside an aminated spinning cog.
COGGERS is a BetterTTV emote, therefore you will need to BetterTTV extension to use the COGGERS emote.

COGGERS Meaning
As COGGERS is an animated variant of POGGERS, it has the same meaning as POGGERS and PogChamp, and is usually spammed at the same time; it is used in moments of excitement when the streamer does something impressive, fun, and or exciting.
It can also be used to express shock or surprise.
COGGERS is not currently in the top 100 BetterTTV emotes that are used on Twitch.
COGGERS Origin
The COGGERS emote can be traced back to 2005 when Matt Furie uploaded the Boys Club comic to MySpace, in which Pepe the Frog was featured, This became an internet meme that was widely adopted on 4chan by 2008 and the rest of the internet including Twitch by 2015
Other variations begin to start being used such as POG and POGGERS, with POGGERS becoming so popular that it was uploaded to BetterTTV in 2017, and due to continued popularity, COGGERS was uploaded to BetterTTV in 2018.